Abstract: The service performance of polycrystalline diamond compact cutters (namely PDC cutters) is highly sensitive to thermal cycling, and excessively high brazing temperatures of bits or repeated brazing times can both lead to degradation of the diamond layer in PDC cutters. To address this issue, three types of PDC cutters were selected and subjected to thermal cycling tests using oxy-acetylene flame brazing of bits. Wear resistance was used as the evaluation criterion to investigate the effects of brazing temperature, brazing times, and run-in-hole cycles on the service performance of PDC cutters. The results indicate that the diamond layer in PDC cutters is isotropic and mutually non-interfering, and slight-to-moderate damage on one side does not affect the performance of the other side. During brazing, the maximum temperature of the bit body reaches 680 °C, and the maximum temperature on the PDC cutter surface reaches 725 °C; no change in wear resistance is observed for any of the three PDC cutters before and after brazing, confirming that the current brazing procedure satisfies production requirements. For the in-house developed PDC cutters, wear resistance remains identical to that of unbrazed cutters after three brazing and debrazing cycles and begins to gradually decline from the fourth brazing as the brazing time increases. For the imported PDC cutters, wear resistance starts to decrease from the third brazing, whereas the domestic PDC cutters exhibit a pronounced decrease starting from the second brazing. These findings provide experimental evidence for understanding the thermal sensitivity of diamond-based materials, validating brazing procedures, and enabling cutter recovery and reuse.