In response to the issue that the density of sodium bromide as a drilling and completion fluid is only 1.52 g/cm3, which is difficult to meet the demand for high-density fluids in deep well operations, this article pro-poses to conduct corresponding solubilization studies on the sodium bromide system using three different solu-bilization methods. Firstly, seven common and low-cost inorganic salts were selected to conduct a solubiliza-tion study on the saturated sodium bromide solution. Then, the solubilization effects of five different types of surfactants and two copolymers on the sodium bromide system were further investigated, and their solubiliza-tion mechanisms were clarified. The research results show that the solubilization effect of the sodium bromide and zinc chloride mixture is the best, which can increase the density of the system from 1.520 g/cm3 to 1.913 g/cm3. When the anionic surfactant LAS-30 and the nonionic surfactant Tween-80 are used in combination, the density of the sodium bromide-zinc chloride complex salt system is further increased to 1.926 g/cm3. When the copolymer AM-AMPS is used to solubilize the sodium bromide-zinc chloride complex salt system, the density can be increased to 1.923 g/cm3. Regarding the solubilization mechanism, when sodium bromide is added to the LAS-30 surfactant, the Zeta potential on the micelle surface increases from -70 mV to -31.73 mV, indicat-ing that the polar shell on the micelle surface and the free ions in the solution have undergone electrostatic ad-sorption. The determination results of the critical micelle concentration (CMC) show that the presence of inor-ganic salts significantly reduces the CMC of the surfactant. For the copolymer system, the microscopic mor-phology changes of the sodium bromide crystals before and after solubilization were compared to analyze whether it causes lattice distortion or complexation.