The invention discloses an automatic leveling device and method for a forward moving type 
forklift truck. The automatic leveling device comprises a transmission mechanism, an angle sensor, a sloping oil cylinder and a controller. One end of the transmission mechanism is connected with a fork frame, and the other end of the transmission mechanism is connected with the angle sensor for transmission. The angle sensor is fixed to a side moving device 
assembly so as to output an 
electric signal in proportional relation with the rotating angle of the fork frame. The sloping oil cylinder is fixed to the side moving device 
assembly, and the pushing end face of the sloping oil cylinder faces the fork frame. The controller is connected with the angle sensor and the sloping oil cylinder and shields other sloping orders and controls the sloping oil cylinder to act when receiving the leveling order until the upper surface of a horizontal section of a fork rotates to the horizontal position. By means of the automatic leveling device and method for the forward moving type 
forklift truck, the closed-
loop control principle is adopted, the 
electric signal output by the angle sensor serves as the 
negative feedback, the sloping angle of the fork is judged, the action of the sloping oil cylinder is controlled, and therefore the fork can be automatically horizontal. The 
control manner is simple, the work efficiency is improved, and the 
safety risk generated when the fork frame forks goods and retreats from a tray in the non-horizontal state is lowered.