Using high-resistivity (10000—20000 Ω·cm) n-type Si wafers,we have developed φ60 PIN semiconductor detector with depletion thickness ～1000 microns for low-intensity pulsed γ-ray flux measurement.For determination of thickness of the depletion depths, a recoil proton chamber with 20° scattering angle has been constructed.The detector's performance have been measured and analyzed,which indicates that the developed detector satisfactorily meets the expected specifications.Compared with the existing detectors with depletion depths of 200—300 microns,the detector has much greater γ detecting sensitivity and suited for measuring pulsed γ-ray flux in low-intensity mixed γ/n fields.