The invention relates to a medium voltage dual power supply operating mechanism which comprises an upper power supply operating mechanism, a lower power supply operating mechanism and an intermediate frame. The upper power supply operating mechanism and the lower power supply operating mechanism are respectively arranged on upper and lower ends of the intermediate frame. Each power supply operating mechanism comprises a mounting frame, an L-shaped bending plate and a spline spindle, wherein the L-shaped bending plate and the spline spindle are provided with a closing transmission mechanism. An L-shaped locking plate is arranged on each mounting frame. An interlocking transmission mechanism is arranged between each L-shaped locking plate and each spline spindle. Locking limit of the L-shaped bending plates is realized through the rotation of the L-shaped locking plates. A synchronous connection link is arranged between the upper interlocking transmission mechanism and the lower interlocking transmission mechanism. After any one of the power supply operating mechanisms in the medium voltage dual power supply operating mechanism carries out closing operation, upper and lower L-shaped locking plates are driven to rotate to limit the closing rotation of upper and lower L-shaped bending plates.