The invention relates to an automatic conveyor, which is characterized in that a conveying platform is arranged by taking a base as a support, the conveying platform is obliquely arranged along the conveying direction in a way that the part loading end of the conveying platform is high and the part unloading end of the conveying platform is low, and backup rolls which can rotate on the conveying platform form a conveying plane; and limiting mechanisms which can be lifted up or lowered down at proper time are respectively arranged at different positions on the conveying platform. The inventionhas the advantages that the structure is simple, the use is convenient, the application scope is wide for different parts to be conveyed and the logistic conveying method by using the gravity of the parts to be conveyed is not limited by the automation level.