A Hall multiprobe facility for measuring accelerator magnetic field was described. It consisted of a long arm with 3 thermostats containing totally 58 Hall probes
a calibration system of magnetic field with high accuracy
and an automatic data acquisition system. Location
temperature constant and calibration of the Hall probes
and data acquisition and processing were described respectively. The significance of stability of Hall probes for the multiprobe facility was presented. The facility has been used in the construction of HIRFL (Heavy Ion Research Facility Lanzhou). It was shown that the requirement for measuring the accelerator magnetic field could he satisfied.