Charged particles passing through the silicon detector will generate electron-holes pairs along their path by ionization process. Positive and negative charge carriers are drifted in opposite directions to the electrode by the applied electric field. Allpix Squared, an open-source software, is able to simulate the physical processes of particles inside the silicon strip detectors, and generate electrons/holes at each electrode, the digital signal (or ADC) is simulated according to the response of the readout electronics. For silicon strip detectors, the ADC signal exhibits large dependences on the impact position and impact angles of the incident particle. To optimize the charge resolution, the effects concerning particle impact position and angle dependencies are taken into account in this paper, finally the charge measurement method, and the reconstructed charge distribution will be presented.