Abstract: Since changing the angle of layer of performs will have an effect on the mechanical property of the composite, flax fiber was used as the reinforcing material in preparing the prefabricated material with polylactic acid fiber which had been subjected to opening, blending and carding. Then the prefabricated material was shaped into flax/PLA fiber composites by moulding pressing technology. The effects of changing the different angle of layer of performs on the tensile and flexural strength of composite were studied, and the fracture mechanisms and fraction morphology of the composite were discussed by using scanning electron microscopy .The results show that the angle of layer of the composite at 90° has the best horizontal orientation tensile, blending strength and module; at o° has the best vertical orientation tensile, bending strength and module.