Abstract: The single crystals of Ba₂CoWO₆ with millimeter size are prepared by spontaneous nucleation method using BaCl₂ as flux. The structure and magnetic properties are characterized by X-ray diffraction, specific heat and magnetic susceptibility measurement. Using pulsed high magnetic field technology for magnetization measurements up to 50 T, a magnetic field-temperature (H-T) phase diagram of Ba₂CoWO₆ is constructed. The results reveal that Ba₂CoWO₆ exhibits magnetic anisotropy, and the inner Co²⁺ ions are in a high spin state at low temperature, accompanied by an incomplete quenching of orbital magnetic moment. Driven by a high magnetic field, the material undergoes a ferromagnetic phase transition into a saturated state at a critical field H_c=30 T.