A handle locking device for a modularized terminal electric appliance is presented. A housing base thereof can be assembled onto any outer side surface of the housing of an appliance through a connection mechanism. There are a horizontal pivoting door and a vertical pivoting door which can be unfolded or folded inside a door hole on a sliding member of the locking mechanism. When unfolded, the horizontal pivoting door mates with an appliance handle to block the reverse motion of the handle, and the vertical pivoting door and the horizontal pivoting door can mate to block the reverse motion of the unfolded horizontal pivoting door. The horizontal pivoting door is pivotally connected to the sliding member through a horizontal pivoting, and the vertical pivoting door is pivotally connected to the sliding member through a vertical pivoting. A padlock is provided with a lock ring which can penetrate the interconnected door hole from a padlock hole and the lock ring can mate with the vertical pivoting door to block the reverse motion of the unfolded vertical pivoting door. The locking mechanism is connected and mounted with the housing base through a moving pair and can only perform up/down sliding along the direction of an assembly reference line B parallel to the appliance height direction Y, the locking mechanism is defined to slide merely between the locking and unlocking positions thereof, and adjustable height position of the locking device under the two states of handle locking and unlocking is realized by way of the shift of the sliding member.