Abstract: Objective Based on the Magphan phantom,a baseline value of low contrast resolution was established,and the stability of the imaging performance of the system was monitored.Drift and correction were found in time to give full play to the performance of the device.Methods The general test evaluation method for low-contrast resolution was not suitable for the characteristics of long-term monitoring equipment performance changes,and the test evaluation of low-contrast resolution that incorporates the t-test method in statistical principle was proposed.Results By analyzing and evaluating the test results of the low contrast resolution of the standard water model image,and verifying the correctness of the evaluation method,according to the correct test method,the test statistic value was used as the low contrast resolution value of the MRI equipment to test the t boundary of the region.The value was used as a baseline value for low contrast resolution to establish a long-term stable quality assurance system.Conclusion In this paper,the data of the low contrast resolution test on Magphan phantom was in line with practical experience,therefore the test method of low contrast resolution was verified.The baseline value of the indicator can be established based on the detection and evaluation method of low contrast resolution based on phantom,then to ensure the stability of the imaging performance of the system.