A contact resistance test method and related devices are provided. When a MOS transistor working in a linear region is tested, a functional relationship between the channel width of the MOS transistor and total resistances of the MOS transistor at sampling temperatures is determined, to determine the contact resistance of the MOS transistor at the sampling temperatures. A calibration coefficient of the contact resistance at a current ambient temperature is determined based on the contact resistance of the MOS transistor at the sampling temperatures. A measurement result of the contact resistance is further adjusted based on the calibration coefficient of the contact resistance at the current ambient temperature, to obtain an accurate contact resistance at the current ambient temperature.