Abstract: In order to increase the single well production and reduce development costs of fractured reservoirs in the Bozhong Block of Bohai Oilfield, a field test of fishbone multi-branch hole stimulation technology was carried out. The technology is characterized by simple tool structure, convenient construction, and low platform burden which make it suitable for offshore platform operation. As the technology is implemented, multi-branch holes with a length of 12 m can be drilled from the main wellbore to the reservoir at one time, and they can penetrate near-well pollution zones, connect the oil and gas flow channels in near-well zones, and improve the single well production, which has great application potential in increasing the production of fractured reservoirs. To ensure the field test could be carried out smoothly, the first step involved a ground test to analyze the drillability of the rock in fractured reservoirs and the trajectory controllability of multi-branch holes. The hydraulic parameters and construction scheme for the fishbone multi-branch hole stimulation technology were optimized accordingly. Furthermore, the field test was carried out in an exploratory well in the Bozhong block. After the application of fishbone multi-branch hole stimulation technology, the well’s gas productivity index and daily gas production were increased by more than 29% and 20%, respectively. The test results showed that the fishbone multi-branch hole technology can improve the single well production of fractured reservoirs in the Bozhong Block of Bohai Oilfield, and provide technical support for the efficient development in the block with low implementation cost.