Field computation, an emerging computation technique, has inspired passion of intel igence science research. A novel field computation model based on the magnetic field theory is con-structed. The proposed magnetic field computation (MFC) model consists of a field simulator, a non-derivative optimization algo-rithm and an auxiliary data processing unit. The mathematical model is deduced and proved that the MFC model is equivalent to a quadratic discriminant function. Furthermore, the finite element prototype is derived, and the simulator is developed, combin-ing with particle swarm optimizer for the field configuration. Two benchmark classification experiments are studied in the numerical experiment, and one notable advantage is demonstrated that less training samples are required and a better generalization can be achieved.