The invention provides an assistant instructing system and an assistant instructing system method based on EON. A three-dimensional model of a mechanical product and a three-dimensional model of a virtual hand are established, up and down motions, left and right motions, front and back motions and rotation of the three-dimensional model of the virtual hand are achieved by a position tracker, a data glove grabs and releases the three-dimensional model of the mechanical product according to gesture change of the virtual hand, namely students master contents narrated by teachers by animation demonstration, and the students can form a brand new understanding on constituent parts, an internal structure, a disassembly process, an assembly process and the like of the mechanical product from a three-dimensional angle by means of 3D glasses through 3D demonstration parts. The assistant instructing system and the assistant instructing system method provided by the invention can be used for achieving the purposes of animation demonstration, manual disassembly, manual assembly, motion simulation and 3D demonstration, compensating the shortcomings in practical teaching of colleges and universities at present, and enabling the students to carry out manual operations when learning theoretical knowledge, which is helpful for the students to deepen the theoretical knowledge and improve the practical application ability.