This paper presents a scheme for the long-distance transmission of cold atomic beams by two-dimensional magneto-optical traps based on the optical dipole force of red-detuned Gaussian beams. The scattering force equation of two-level atoms is used to analyze the forces on ⁸⁷Rb atoms in a two-dimensional magneto-optical trap with an optical dipole trap (2D-ODT MOT). In consideration of collisions of atoms with the background gas, the equations of atomic motion are solved by the fourth-order Runge-Kutta method and the trajectories of the atoms are obtained. The number of atoms entering the differential pumping range at different detunings of Gaussian beams and different powers is counted. Finally, the loading of cold atoms in magneto-optical traps of the science chamber is experimentally verified for four operating states in which the red-detuned Gaussian beam and the push light of atomic beams are combined. The theoretical and experimental results show that the 2D-ODT MOT based on the red-detuned Gaussian beam is effective in transmitting cold atomic beams over long distances. Both the loading efficiency and the number of atoms loaded in the science chamber are increased significantly.