Provided is a method for controlling smooth switching of an operation direction of a bidirectional resonant CLLC circuit, which applies to the bidirectional resonant CLLC circuit. The method includes the following steps: Step 1: detecting a current circuit state and controlling the bidirectional resonant CLLC circuit to operate in a forward operation state by means of a primary bridge and a secondary bridge, by a controller; Step 2: performing Step 3 when an externally transmitted reference signal received by the controller or an internal preset reference signal in the controller is an operation direction switching signal; Step 3: performing frequency conversion control, by the controller; Step 4: performing preparation of phase shift control and generating a driving signal of the secondary bridge, by the controller; Step 5: performing the phase shift control, by the controller; and Step 6: switching a circuit operation state to an inverse operation mode.