In order to study the stability change of double loop natural circulation under asymmetric conditions, taking the single loop natural circulation heat carrying system as the starting point, the displacement term in the dimensionless governing equation set of single loop natural circulation is expanded by Fourier expansion, and the Jacobi matrix characterizing the single loop natural circulation heat carrying system is obtained, and verification is conducted. On this basis, the Jacobi matrix analysis model of double loop is constructed. Based on...