In order to solve the problems of the preparation and matching characteristics of key materials in the development of large area and large power molten carbonate fuel cell(MCFC) stack, the assembly and test operation method of 10 kW MCFC stack is proposed. In this paper, the preparation method of matrix and electrode for large area MCFC is proposed. A 10 kW class MCFC power generation system with 120 cells and an effective area of 0.2 m2 for each cell is assembled and operated. In the constant voltage discharge test, the maximum output power is 16.51kw and the current density is greater than 95 mA/cm2. In view of many experiments and analysis, an effective online evaluation method for the baking effect of MCFC electrolyte matrix is obtained, which makes the matrix, electrode and molten salt electrolyte in the molten carbonate fuel cell body form a good match, which has an important guiding significance for improving the assembly and long-term operation of MCFC battery stack. The development and performance test method of the MCFC stack in this paper will provide effective theoretical and experimental guidance for the subsequent development of the larger MCFC power generation system, which is of great significance to promote the commercial demonstration and promotion of MCFC.