The utility model discloses a high reliability speed detector for an electronic belt conveyor scale. The high reliability speed detector comprises a speed detecting roller (1), wherein two ends of a transmission shaft (2) of the speed detecting roller are fixedly connected with a bearing seat (3), one end of the transmission shaft of the speed detecting roller extends outwards, the tail end of the transmission shaft is connected with a sensor (4), the outer surface of the speed detecting roller is provided with multiple contact members (5) extending along the radial direction of the speed detecting roller, tail ends of the contact members are provided with bending portions, and bending directions of the bending portions and a belt motion direction of the electronic belt conveyor scale are consistent. The high reliability speed detector is advantaged in that: surface contact between a speed detecting roller and a belt in the prior art is replaced by line contact, influence on motion of the belt is reduced, and detecting reliability is improved; the bending direction of the tail end bending portions of the contact members are designed to be consistent with the motion direction of the belt, the tail end bending portions of the contact members and the motion direction of the belt are in tangent relations, the tail end bending portions of the contact members and the belt keep constantly synchronous, and influence on the belt is reduced; and the high reliability speed detector has advantages of simple structure and accurate measurement data.