We propose a 10 kW fiber laser by using home-made large mode field gain fiber, passive components and dual-end-pumping technique to suppress nonlinear effects. A power amplifier with output power of 10.14 kW, wavelength of 1070.36 nm and 3 dB bandwidth of 5.32 nm is established. For the main amplification stage, the maximum optical-optical efficiency is 87.8% and the slope efficiency is up to 89.2%. To the best of our knowledge, the proposed laser is the most efficient 10 kW-level fiber laser reported in China.