The invention aims at providing a steel bar detection apparatus in order to address the technical problems of detecting the weight and diameter parameters of a steel bar by using intelligent means. The steel bar detection apparatus includes a cabinet, a feeding system, an auxiliary support system, a diameter detection system, a weight detection system, a hydraulic system and a control system. According to the invention, the steel bar detection apparatus has the following beneficial advantages: the feeding system can automatically acquire to-be-detected samples, reduces manpower, lowers the danger for workers in moving the samples from piles of raw materials, and can automatically transfer the samples to the auxiliary support system. The auxiliary support system can slowly place the samplesto the weight detection system, prevents the weight detection system from damage which may be caused by violently placing the samples. The weight detection system and the diameter detection system can separately detect the weight and the diameter of the steel bar in an intelligent manner.