The invention relates to the technical field of petrochemical engineering and especially relates to a storage tank corrosion-resistant sealing detection device. The device comprises a margin plate mechanism, a horizontal transmission mechanism, a vertical transmission mechanism and a ring beam. The margin plate mechanism is arranged above the ring beam. The horizontal transmission mechanism is arranged above the margin plate mechanism. The vertical transmission mechanism is arranged below the margin plate mechanism. From a position above the margin plate mechanism and the ring beam, corrosion-resistant layers cover the surfaces of the margin plate mechanism and the ring beam, and then the margin plate mechanism produces horizontal displacement through the horizontal transmission mechanism and the margin plate mechanism produces vertical displacement through the vertical transmission mechanism. The device can determine and evaluate a corrosion-resistant layer anti-deforming capability in margin plate mechanism deformation, and can determine and evaluate integrity of a corrosion-resistant layer at the outer edge of the margin plate mechanism and a debinding capability of a corrosion-resistant layer above the ring beam so that the corrosion-resistant sealing material used on site is determined and corrosion-resistant sealing failure between the storage tank bottom plate outer margin plate and a ring beam base is avoided.