Embodiments of the present invention disclose a frequency mixing circuit and a method for suppressing local oscillation leakage in the frequency mixing circuit, where a mixed input signal and a local oscillation signal are involved, and local oscillation leakage can be effectively reduced by using a frequency mixing circuit whose structure is simpler and is easier to be implemented. The frequency mixing circuit includes a direct current bias circuit, where the direct current bias circuit includes a direct current bias voltage source used for reducing a local oscillation current. The frequency mixing circuit is mainly applied to frequency mixing, and especially to a case where an intermediate frequency signal is mixed with a local oscillation signal to output a radio frequency signal.