The invention provides a testing device and a testing method for a single-row or double-row slide-resistant pile action mechanism model. The testing device comprises a model box and a loading device. The model box comprises an inclined landslide surface breast board. Side face breast boards are vertically arranged on two sides of the inclined landslide surface breast board, a bottom breast board is vertically arranged at the bottom end of the inclined landslide surface breast board, and a loading plate is horizontally arranged above the inclined landslide surface breast board; the inclined landslide surface breast board, the two side face breast board, the bottom breast board and the loading plate jointly form a soil accommodating space; a slide-resistant pile group is vertically arranged in the soil accommodating space; and the loading device comprises a jack which applies a force to the loading plate. The testing device and the testing method can research soil pressure development and change of soil bodies around the pile and a pile body stress rule of the single-row or double-row slide-resistant piles in different working conditions so as to disclose the action mechanism of the single-row or double-row slide-resistant piles.