The DArk Matter Particle Explorer (DAMPE)can detect electrons and photons from 5 GeV to 10 TeV and charged nuclei from a few tens of GeV to 100 TeV. The silicon–tungstentracker (STK), which is composed of 768 singled-sided silicon microstrip detectors, is one of four subdetectors in DAMPE providing photon conversion, track reconstruction, and charge identification for relativistic charged particles. This paper focuses on the charge identification performance of the STK detector. The charge response depends mainly on the incident angle and the impact position of the incoming particle. To improve the charge resolution, a reconstruction algorithm to correct for these parameters was tested during a test beam campaign conducted with a high-intensity ion beam at CERN. This algorithm was successfully applied to the ion test beam and the ion charge of Z=4∼10 and was successfully reconstructed for both normal and 9°incident beams.