Abstract: At present, the formation test technology with the multiple flow evaluator (MFE) as the dominant, which accomplishes well opening and shutdown by hoisting up or setting down testing string, can not completely meet the requirements of the formation testing production and the safety and environmental protection for high-pressure oil and gas wells. The YKDL down hole electronic MFE for pressure-controlled intelligent wells is designed for well opening and shutdown without touching the pipe string. Driven by micro-motors, the multiple switching of the mechanism is controlled by outputting the command through the circuit to the control unit according to the intelligent time set in advance. Then the power from the power source is outputted to the switching controlling mechanism and enables it to roll, as a result, realizing the opening or closing of the switching. When something changes in the field, annulus pressure of cementing trucks is utilized on the ground, leads to the formation of pressure codes for well opening and shutdown. Then the switching mechanism is opened or closed. The shortcomings of MFE and the technological mechanism of new tools are introduced, in particular, the structure principle, technical features, and field application of the YKDL MFE are discussed. The diversifying development of the formation testing tools is also put forward.