A testing fixture for a cell temperature probe includes a microcomputer, a temperature probe, a measurement case, a temperature instrument and heaters. The microcomputer configured to receive a control command for executing a testing process. The measurement case has an outer surface and an inner surface. The outer surface includes a probe-contacting area used for being contacted by the cell temperature probe within a formation device in the testing process. The temperature instrument is electrically connected to the microcomputer and has a sensing terminal disposed on the inner surface of the measurement case. The location of the sensing terminal is aligned with the probe-contacting area in a direction of a thickness of the measurement case. The heaters are electrically connected to the microcomputer and thermally to the measurement case.