The invention discloses an online verification and intelligent diagnosis method for the state of substation secondary equipment, which comprises the following steps: step 1, substation model data, a secondary circuit visualization unit, a pre-communication unit and an online verification timer are initialized, and an implementation environment is constructed; step 2, a state sheet of the secondary equipment is preset; step 3, the state of the secondary equipment is recognized at first when online verification is manually triggered on the secondary circuit visualization unit, then state verification is performed according to the state sheet of the secondary equipment and current section data of the secondary equipment, whether the two states are consistent or not is verified, and then an intelligent diagnosis report is provided; when the online verification timer is triggered at the predetermined time, online verification is performed sequentially in allusion to all states of the secondary equipment of the substation, the state of the secondary equipment is recognized at first, then state verification is performed according to the state sheet of the secondary equipment and current section data of the secondary equipment, whether the two states are consistent or not is verified until all equipment are verified, and an intelligent diagnosis report is provided.