In view of the significant computational resources required for numerical simulation of electromagnetic comprehensive performance in modern electrical equipment, and the security and transaction fairness issues of existing delegated computation schemes, we propose a delegated computation scheme under the blockchain framework that is suitable for numerical simulation of electromagnetic comprehensive performance. This scheme combines the multi-level data characteristics of electromagnetic field numerical simulations with practical needs. Firstly, we propose a method for handling multi-layered data in delegated computation. Secondly, we design a delegated computation architecture that involves at least three participants and a detailed transaction mechanism, and develop three smart contracts to ensure data privacy protection and transaction fairness in delegated computation. Finally, the feasibility of the proposed scheme is proved by delegated computations for “Solving the Poisson equation of two-dimensional electrostatic field” and “Optimization of amorphous alloy transformer”. The research results have achieved a reliable and credible solution to the large-scale data computing problem in the field of numerical simulation of electromagnetic comprehensive performance, and provided a new theory and solution for data security in this field.