Abstract: In order to study the effect and mechanism of laying process parameters on the curve trajectory placement quality of prepreg tow, an automated fiber placement simulation test platform was designed and built firstly, and the test of curve trajectory placement was carried out by changing the laying process parameters and laying radius. The laying quality was represented by the measurement and calculation of effective tack width ratio, wrinkle angle and curvature radius ratio and also the results of peeling test of variable laying process parameters. The results show that the curve trajectory placement quality is closely related to the tack and bending stiffness of prepreg tow. With the increase of laying temperature, pressure and tension and the decrease of laying velocity, the tack of prepreg tow increases and the curve trajectory placement quality is improved. Due to the increase of laying temperature, the bending stiffness of the prepreg tow decreases, which can improve the accuracy of laying. However, excessive temperature will cause the tack of the prepreg tow to decrease, make the defect of curve placement obvious. The laying tension will change the stress state of the prepreg tow, thus affecting the accuracy of the laying path. In addition, the smaller the curve placement radius is, the more sensitive the placement quality is to the change of process parameters.