Child safety seat

1. A child safety seat wherein the child safety seat comprises:

an ISOFIX assembly comprising a support foot, a connecting portion, and a sliding rail portion disposed between the support foot and the connecting portion, the connecting portion being configured to connect a car seat, the sliding rail portion comprising a first sliding rail portion and a second sliding rail portion connected to the first sliding rail portion, a width of the second sliding rail portion being larger than a width of the first sliding rail portion; and

a base having a frame assembly, the frame assembly having a sleeve portion slidably sleeved on the sliding rail portion, the sleeve portion comprising a first sleeve portion slidably sleeved on the first sliding rail portion and a second sleeve portion slidably sleeved on the second sliding rail portion, the base being operable to be adjusted telescopically with respect to the ISOFIX assembly through a sliding cooperation between the sliding rail portion and the sleeve portion.

2. The child safety seat of claim 1 further wherein the base further has an operating mechanism and the operating mechanism is operable to control the sliding cooperation between the sliding rail portion and the sleeve portion.

3. The child safety seat of claim 2 further wherein the operating mechanism is disposed on the frame assembly, the operating mechanism comprises an engaging device, and the engaging device comprises an engaging hook for engaging with the ISOFIX assembly.

4. The child safety seat of claim 3 further wherein the operating mechanism further comprises an operating member connected to the engaging device and the operating member is operable to drive the engaging hook to unlock the ISOFIX assembly.

5. The child safety seat of claim 4 further wherein the engaging device further comprises a fixing bracket and the engaging hook is connected to the operating member through the fixing bracket.

6. The child safety seat of claim 5 further wherein the operating member has a driving groove, the fixing bracket has a fixing pillar extending into the driving groove, and the operating member is operable to enable the driving groove to drive the fixing pillar to move, such that the engaging hook unlocks the ISOFIX assembly.

7. The child safety seat of claim 4 further wherein the engaging device further comprises an elastic member and the elastic member drives the operating member to return, such that the engaging hook engages with the ISOFIX assembly.

8. The child safety seat of claim 4 further wherein the operating member has a button and the button is operable to enable the operating member to drive the engaging hook to unlock the ISOFIX assembly.

9. The child safety seat of claim 8 further wherein the base has a through hole and the button passes through the through hole.

10. The child safety seat of claim 3 further wherein the first sliding rail portion has at least one engaging hole engaged with the engaging hook.

11. The child safety seat of claim 1 further wherein the sliding rail portion of the ISOFIX assembly is Y-shaped.

12. The child safety seat of claim 1 further wherein the first sliding rail portion is a straight tube, the second sliding rail portion is a U-shaped tube, an opening end of the U-shaped tube is connected to the connecting portion, and a side of the U-shaped tube opposite to the opening end is connected to the straight tube.

13. The child safety seat of claim 12 further wherein the U-shaped tube is connected to the straight tube.

14. The child safety seat of claim 12 further comprising a decorative cover member is disposed within the U-shaped tube and the decorative cover member is connected to the U-shaped tube.

15. The child safety seat of claim 1 further wherein the connecting portion has two connecting rods and the two connecting rods are configured to connect an anchor port on a car seat.

16. The child safety seat of claim 1 further comprising a sliding sleeve disposed between the second sliding rail portion and the second sleeve portion.