This paper introduces a type of control and test system for internal combustion engine based on Serial bus and virtual instrument technique. It consists of host and intelligent node, with parameter signals communication through RS485 serial bus to form a distributed high-precision status parameters controlling testing system. The host computer implements the user interaction, data storage, status monitoring, power measurement and computation as well as management. The client unit reads the commands of host, controls the rotation speed of engine and excitation current, detects all the parameters of system and transmits the data. The hardware and software structure of the distributed testing system (client) with ATmega128 micro single chip computer and communication module are implemented. And the application software was developed with graphical virtual instrument language LabVIEW. The solution may have some reference value to the design of other internal combustion monitoring system with other control bus and the development of general single chip microcomputer and industrial field monitoring and controlling system.