The utility model discloses a variable gravity balancing device, wherein an upper locking disc which is formed by pin joint of two semicircular plates and a lower locking disc which is formed by pin joint of two semicircular plates are sleeved on an upright post of a supported device; one semicircular plate of the upper locking disc is connected with one semicircular plate of the corresponding lower locking disc through two tension rods; tension rods which are exposed to the outside of the upper locking disc are respectively hinged with endpoints of respective push-off pins; one end of each of two gas springs is respectively arranged on the other semicircular plate of the lower locking disc through a hinged seat and the other end of each of the two gas springs is respectively hinged on a push-off pin close to one end of each tension rod; and guide holes on both sides of a lantern ring are respectively sleeved inside respective push-off pins and axially slide along the two push-off pins. The variable gravity balancing device can adjust the size and the direction of the counterweight according to practical situations, so as to achieve the optimum gravity balancing effect; the whole balancing mechanism is connected with the supported device through a locking device; the prior structure of the supported device is not required to be changed; and the variable gravity balancing device is convenient to disassemble and maintain.