Abstract: The reinforced effects of two kinds of diabase were compared. The dosage of the fiber and the types of coupling agents were studied which influence the mechanical properties. SEM was used to analyze and test the structure of the diabase/PVC composites. Conclusions are as follows: the reinforced effect of No.1 diabase is preferable. With the addition of diabase, the strength of the composite first increases and then decreases.The results show that the mixed coupling agent is the best choice.