The present invention discloses a calibration method and calibration circuit for a wireless transceiver. The wireless transceiver includes a transmission path and a reception path, and there is a mixer on the transmission path. The calibration method includes the following steps: (A) adjusting a first parameter of a first LC tank circuit of the mixer; (B) receiving a first input signal via a coupling path and the reception path; (C) measuring a first power of the first input signal; (D) repeating steps (A) to (C) to obtain multiple first powers; and (E) determining a first target parameter corresponding to a largest power of the first powers.