With the development of electrification, it has been paid more and more attention to the electromagnetic compatibility in electrical and electronic systems. To suppress the effects of electromagnetic interference and achieve electromagnetic compatible operation of equipment or components, it is necessary to research the crosstalk between cables. However, few researches have focused on the electromagnetic crosstalk between double differential mode loops consisting of a generator loop, a receptor loop, and the ground. In this paper, a five-conductor transmission line model based on the multi-conductor transmission line theory is proposed, and the crosstalk between double differential mode unshielded cable loops is researched based on it. According to the coupling mechanism, the method firstly establishes the equivalent model of unit-length five-conductor transmission line, then writes the system of Kirchhoff equations according to the method of finite difference, and finally solves the equations after supplementing the boundary conditions to obtain the crosstalk in the frequency domain. The crosstalk calculation results are compared with the simulation results of CST software to verify the feasibility and validity of the model and calculation method. The inductive coupling and capacitive coupling are studied respectively by the calculation, and the influence laws of different factors on the cable crosstalk are obtained by calculation and analysis, which can provide guidance for taking measures to suppress cable crosstalk in practical engineering.