An electric toy gun with a single fire mode, a dual fire mode and a continuous fire mode is disclosed to include a trigger (1), a power break holder (2), a power contact holder (3), a gearwheel set (4), a block member (23) horizontally slidably coupled to the power break holder (2) and having a first tooth (231) and a second tooth (232) at one lateral side thereof, a swing bar (5) having an actuation portion (51) and a push block (52) connected to the actuation portion (51), and a control mechanism (6) controllable to enable the push block (52) of the swing bar (5) to be selectively shifted to the rear side of the first tooth (231), the rear side of the second tooth (232) or the front side of the second tooth (232) when the trigger (1) is pressed and the power break holder (2) with the block member (23) are lowered so that the swing bar (5) can be driven to force the push block (52) to move the first tooth (231) forward, or first to force the push block (52) to push the second tooth (232) forward and then to push the first tooth (231) forward, moving the block member (23) away from the stop portion (122) of the link (12) to cause the power break holder (2) away from the power contact holder (3) in turning off power supply, or to keep the push block (52) away from the first tooth (231) and the second tooth (232) for enabling the power break holder (2) to be moved upward to turn off power supply when the trigger (1) is released.