Transition metal selenides (TMSes) have garnered considerable interest as potential electrode materials for supercapacitors owing to their promising electrochemical properties, but the fabrication of intricate nanostructured electrodes utilizing these compounds still poses a formidable challenge. In this study, a ternary transition metal selenide nanomaterial Cu2MnSnSe4, which has rarely been reported, was successfully synthesized on nickel foam (NF) by a simple solvothermal method, and its electrochemical properties have not been concern by researchers. We systematically studied the electrochemical properties of the materials synthesized under different solvothermal reaction times, and discussed the relationship between reaction time and electrochemical properties. The unique porous surface architecture of the sea urchin-like nanosphere configuration in Cu2MnSnSe4 material grants it a significantly enhanced specific surface area and a proliferation of electrochemically active sites, surpassing those of other comparable materials. According to the synthesis reaction time from short to long, the materials were named Cu2MnSnSe4-1 (20h), Cu2MnSnSe4-2 (25h) and Cu2MnSnSe4-3 (30h), among which Cu2MnSnSe4-2 showed better electrochemical performance than the other two. Electrochemical results show that the prepared Cu2MnSnSe4-2 electrode possesses an outstanding specific capacitance of 930.6 mF cm−2 at 2 mA cm−2, good rate performance (92 %), and a capacitance retention rate is 67.57 % after 3000 cycles of charging and discharging. The asymmetric supercapacitor (ASC) exhibits a voltage window spanning 0–1.6 V, reaching an outstanding energy density of 0.076 mWh cm−2 at 1.47 mW cm−2. Remarkably, it maintains 129.63 % cycling stability even after enduring 5000 charge-discharge cycles. From the above results, it can be seen that Cu2MnSnSe4 material may be a promising electrode material with broad application prospects in the practical application of supercapacitors.