High-power fiber laser oscillators have been widely used in industrial processing, material processing, biomedical and other fields due to their compact structure, simple logic and strong power scalability. With the continuous improvement of performance requirements for lasers in industrial applications, bidirectional output fiber laser based on a single resonator structure have a broad application prospect. This paper first establishes a theoretical model for a 1050 nm bidirectional output fiber laser oscillator based on the steady-state rate equation, and simulates the relationship between the length of the gain fiber and output power, efficiency, and the intensity of stimulated Raman scattering (SRS). A high-power bidirectional output fiber laser with a central wavelength of 1050 nm is built using an ytterbium-doped fiber with a core/cladding diameter of 20/400 μm. The output characteristics of the 1050 nm bidirectional output fiber laser oscillator under different pump methods (unidirectional pump, bidirectional pump) are experimentally studied in detail. With a total pump power of 5262 W, A-end output power of 1419 W and B-end output power of 3051 W were achieved, with a total output power of 4470 W, and the optical-to-optical conversion efficiency reached 84.9%. The corresponding beam qualities (M²factor) of both ends were 1.27 and 1.31 when the output powers reached 1458 W and 2733 W, respectively. By further optimizing the length of the gain fiber, the amplified spontaneous emission (ASE) and SRS were effectively suppressed. With a total pump power of 5262 W, the Raman suppression ratios at A-end and B-end were increased by about ~6.6 dB and ~8.1 dB, respectively. It is expected that higher output power can be achieved by increasing the pump power and optimizing the laser structure in the future.