The invention discloses a power transmission joint defense inspection system which comprises a base, a programmable controller set on the base, and a camera connected with the programmable controller. A left walking mechanism and a right walking mechanism of the same structure are arranged on the base. A locking and de-icing mechanism is arranged between the left walking mechanism and the right walking mechanism. A foreign body disposing mechanism is arranged at the left side of the left walking mechanism. The condition of transmission lines can be observed, and foreign body disposal is efficient and effective.