The utility model relates a horizontal well logging well mouth guide device which is applied to oilfield logging cable guiding. The horizontal well logging well mouth guide device is characterized in that two centered fixed pulley support plates are welded on the outer wall of a casing joint, a centered fixed pulley is arranged at the upper end of each centered fixed pulley support plate, a screw rod joint is arranged below each centered fixed pulley support plate, a screw rod is fixed at the other end of the screw rod joint, two rotating pins are respectively inserted in rotating pin holes which are formed in the lower end portion of two guide pulley support plates, a guide pulley shaft is arranged in a shaft pin hole which is formed in the upper end portion of each of two guide pulley support plates, a shaft pin enables a connecting plate to be connected in the middles of the two guide pulley support plates, and one end of the connecting plate is connected at two ends of a hinge pin. The horizontal well logging well mouth guide device is used for horizontal well pumping testing, and ensures that a cable joint can smoothly pass through a well mouth and avoid an operation machine travelling block. The abrasion between a cable and the operation machine travelling block is reduced, the cable is protected from being worn, safety of horizontal well construction is guaranteed, and well logging efficiency is enhanced.