In order to solve the problem that 7075 aluminum alloy with low extension rate cracked in the process of selfpiercing riveting(SPR), a method of preheating treatment of 7075 aluminum alloy was put forward. Connecting the 7075 aluminum alloy plate with the thickness of 2 mm as the lower plate with the RC5754 aluminum alloy plate with the thickness of 12 mm as the upper plate by the SPR riveting gun, the SPR riveting quality before and after preheating treatment was compared.As well as, the tensile experiments of 7075 aluminum alloy plates before and after preheating treatment were made and compared. The experimental results show:the extension rate of 7075 aluminum alloy is improved after preheating treatment. The problem of appearing cracks in SPR riveting process is solved by preheating treatment.