The invention discloses a fully-adaptive skip-level-protection-preventing method suitable for a complex power distribution network. The method mainly comprises a skip-level-protection-preventing device, a switch, a communication cable and an optical cable. The skip-level-protection-preventing device is connected to a main communication network through the switch, and has an inter-phase fault detection function and a small-current grounding fault detection function of over-flow-rate disconnection. The skip-level-protection-preventing device automatically identifies the hierarchical position ofitself in a power distribution network system through GOOSE message containing locking information sent by a subordinate protection device. When the power distribution network breaks down, the skip-level-protection-preventing device judges the faults and combines the received GOOSE locking information to carry out fault tripping, fault locking or delay tripping, and meanwhile, according to the fault direction and the received locking information, sends a locking signal to an upper-stage protection device in the positive direction or the reverse direction, so that an skip-level-protection-preventing function of the whole power distribution network is achieved, correct selection and tripping isolation faults of faults are ensured, and safe and stable operation of the power grid is achieved.