This is a phase I clinical trial conducted in participants with PSMA-positive metastatic castration-resistant prostate cancer (mCRPC). After confirmation of PSMA positivity, participants receive intravenous administration of 177Lu-PSMA-VG01. The objectives are: to evaluate the biodistribution, radiation dosimetry, safety and tolerability of 177Lu-PSMA-VG01 in participants; and to assess the pharmacokinetics (PK), preliminary anti-tumor activity, and in vivo stability of 177Lu-PSMA-VG01 in participants.