The performance of the aramid III composite product is affected by the molding process parameters. Through the analysis of the prepreg molding process, it is found that the prepreg placement time is the main parameter that affects the interlaminar shear strength（ILSS） of the aramid III composite. In order to study the influence and sensitivity of the prepreg placement time on the ILSS of the aramid III composite material, the short beam method interlaminar shear experiment method was used to obtain the corresponding strength values of the prepreg under different placement time. According to the experimental data, the regression model of the process parameters on the ILSS was established, and the reliability and validity of the regression model were verified by the residual error, the comparison between the predicted value and the actual value. Using this regression model can accurately give the ILSS of the aramid III composite under different storage time of the prepreg, and obtain a single parameter sensitivity curve. Through the analysis of the sensitivity curve, the stability and instability range of the parameters can be determined. The experimental results show that as the placement time increases, the ILSS of the aramid III composite material increases first and then decreases. The optimal prepreg placement time corresponding to 0°/0°, 0°/90°, ±45° layup is within the range of 10～22 h. Within this range of process parameters, the aramid III composite material can be guaranteed to have the maximum ILSS.