Carbon fiber reinforced thermoplastic（CFRTP） are widely used in aerospace and automotive industries owing to its lightweight and high strength. The joining of CFRTP and aluminum alloy is still an urgent problem to be solved. The common joining are adhesive bonding and mechanical connection,but adhesive bonding procedure is complicated and the adhesive is easy to age,and the mechanical connection will cause stress concentration. Laser welding can realize the welding of CFRTP and aluminum alloy because of its high welding efficiency,energy concentration and easy industrial production. The strength of laser welding joints after different surface treatments and welding power range are studied,and the joining mechanism of laser welding between aluminum sheets and CFRTP is revealed by microscopic characterization.