WAP four-disulfide core domain 2 (WFDC2) is a small secretory protein that has been widely studied in ovarian cancer. It has been proven that WFDC2 promotes proliferation and metastasis in ovarian cancer, and serves as a diagnostic biomarker. However, the specific function of WFDC2 in prostate cancer has not been reported. Here, we first screened the diagnostic marker and favorable prognostic factor WFDC2 in prostate cancer by bioinformatics. WFDC2 expression was negatively correlated with Gleason score and metastasis in prostate cancer. Then, we revealed that overexpression of WFDC2, and addition of recombinant protein HE4 can significantly inhibit prostate cancer metastasis in vivo and in vitro. By co-immunoprecipitation and co-localization assays, we proved that WFDC2 binds to the extracellular domain of epidermal growth factor receptor (EGFR). Immunoblot showed that WFDC2 overexpression and recombinant protein HE4 addition inactivated the EGFR/AKT/GSK3B/Snail signaling pathway, and then restrained the progression of epithelial-mesenchymal transition. In conclusion, our study identified that the tumor suppressor WFDC2 can suppress prostate cancer metastasis by inactivating EGFR signaling.