This is a pilot study to assess the safety and measure image-based absorbed dose of 177Lu-P17-087/177Lu-P17-088 in patients with metastatic castration-resistant prostate cancer (mCRPC) who will undergo radioliagnd therapy using 177Lu-P17-087/177Lu-P17-088. All patients underwent whole-body 68Ga-PSMA PET/CT for selection and accepted intravenous injection with single dose 1.1 GBq (30 mCi) of 177Lu-P17-087/177Lu-P17-088 within one week, then monitored at 1.5 hours, 4 hours, 24 hours, 48 hours, 72 hours, 120 hours and 168 hours after 177Lu-P17-087/177Lu-P17-088 administration with serial whole body planar and SPECT/CT imaging.Following this initial safety assessment, the study will proceed to a dose-escalation phase designed to further evaluate safety and determine the optimal therapeutic activity. The dose-escalation phase will enroll patients into three sequential cohorts: a 1.11 GBq (30 mCi) dose group, a 2.96 GBq (80 mCi) dose group, and a 4.44 GBq (120 mCi) dose group.