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Objective In the process of tumor thermotherapy, MRI scanner can monitor the temperature changes of the heated area. The measurement accuracy of T1-weighted imaging thermometry involves the parameters of imaging sequences. To supply more references for clinical MRI thermometry and improve the accuracy of MRI thermometry, this article investigates the influences of the parameter of spin-echo (SE) sequence: repetition time (TR) on the accuracy of MRI thermometry based on the theory of T1-weighted imaging. Methods Based on the theory of T1-weighted imaging thermometry, this study scans the porcine liver tissue of different temperatures under a 0.4 T MRI scanner with SE sequence with different TR. In order to quantify the influence of TR on the thermometry accuracy of MRI, the fitting relationship of the signal intensity of T1-weighted image and temperature should be figured out. Subsequently the theoretical temperatures measured by different SE sequences are compared with actual temperatures measured by digital thermometer. Results Parameter TR can affect the accuracy of the MRI thermometry to a large extent. Under the condition of the experiment, when TR is 400ms (TE is fixed at 18ms), the temperatures measured by this SE sequence are most close to the actual temperatures. The temperature deviation remains around ±1℃. Conclusions In the process of MRI thermometry, proper TR of SE sequence can improve the thermometry accuracy to a large extent. This study has certain reference value and important directive significance for clinical thermotherapy.