Generally, the coefficient matrix of equation system is symmetric white the finite element method is used for questions on fluid dynamics, heat transfer and other engineering subjects. If there is a restrictive condition with the form of Q_i=Q_i G, where Q_i and Q_i are respectively the ith and jth variables of equation system, G is a constant. The methematical treatment method provided in this paper can be used to make the original equation system with symmetrical and positive definite quality to be a new equation system with symmetric quality after relieving the restrictive condition mentioned above. The mathematical treatment has been justified in this paper and an ALGOL computational program is compiled.