The invention relates to a simple hole verifier and an application method thereof. The simple hole verifier comprises a fixed cross, a falling cross and a suspension wire joining the fixed cross and the falling cross, wherein the fixed cross is formed by hinging two upper arms, the hinged position of the two upper arms is provided with a threading hole, the lower surface of each upper arm is symmetrically provided with an upper arm extension rod about the center, the falling cross is formed by hinging two lower arms, each lower arm is symmetrically provided with a balance adjusting bolt by adopting a hinge shaft as a center, two end parts of each lower arm are respectively provided with a second adjusting screw and a pair of lower arm extension rods which are fixed below the lower arms. The simple hole verifier is simple in structure, low in cost, flexible to use and simple and practical in operation process; a function for measuring aperture of a pile hole and a function for measuring the verticality of the pile are integrated, so that flexibility in adjustment can be realized according to the on-situ situation, not only can the accuracy in measurement be guaranteed, but also the measurement working efficiency can be guaranteed, and the success in work can be favored. The simple hole verifier can be widely used for measuring the aperture and the verticality of the pile hole.