The invention provides a wire cutting force testing device. The wire cutting force testing device comprises machine tool body, a spindle chuck, a pull type tailstock, a guide track, a wire clamping assembly, an observing and collecting assembly and a tool bit assembly. The invention further provides a wire cutting force testing method, the testing device is used in the method, cutting force in a wire cutting machining process is tested rapidly and conveniently by the steps of machine tool coaxiality detection, wire clamping and fixing, tool bit assembly mounting, trial cutting and formal cutting sequentially, numerical values can be read in an on-line manner in real time, and the testing device is simple in structure, facilitates clamping and is simple and convenient to operate. The wire cutting force testing device and device have the advantages that data can be collected and concluded by a computer software technology in the earlier stage of cutting, a cutting force value is analyzedin an online manner by a mathematical method, the applicability and practicality are high, requirements for measurement of turning force of wire metal parts can be met, the quality of the products isstable and the like.