The invention discloses a mechanical quick-hole-formation construction method for an improved simple rectangular anti-slide pile. The method comprises the specific steps that A, a rectangular pile hole is subjected to paying-off and positioning; B, a rectangular steel pile casing is manufactured; C, a rotary digging pile machine performs hole digging according to the pile core sequence number andposition; D, a hydraulic vibration hammer is used for downwards placing the rectangular steel pile casing into the rectangular pile hole, and excess earth is removed; E, an overbreak area of the outerside of the steel pile casing is poured with concrete; F, the hydraulic vibration hammer is used for taking out the steel pile casing; G, a rectangular reinforcement cage is downwards placed and poured with concrete to form the anti-slide pile. The construction method solves the problems of slow construction progress and extremely high hole formation difficulty of a manual digging pile and has the advantages of being convenient to operate, safe to construct, high in efficiency and wide in application range.