An electric outboard motor for a boat, comprising a main body , a motor , a motor controller , a motor mounting case , a paddle , a paddle shaft , a speed-adjusting handle assembly and a main body overturning locking mechanism ; wherein, the motor mounting case is mounted on the main body , the motor and the motor controller are arranged inside the motor mounting case , the motor is electrically connected with the motor controller , one end of the paddle shaft is arranged in the main body , the other end extends out of the main body and is sleeved with the paddle , and a motor shaft of the motor is in transmission connection with one end of the paddle shaft through a transmission component ; the speed-adjusting handle assembly is hinged on the motor mounting case , the speed-adjusting handle assembly includes a handle shell (7-1), a potentiometer (7-2) and a potentiometer mounting board (7-3), the potentiometer (7-2) and the potentiometer mounting board (7-3) are both arranged in the handle shell (7-1), the potentiometer (7-2) is electrically connected with the motor controller , and the potentiometer (7-2) is mounted on the potentiometer mounting board (7-3); the main body overturning locking mechanism includes a spindle mounting base (8-2), a mounting hook (8-3) and a first spindle (8-4), and the spindle mounting base (8-2) is connected with the main body in a rotation manner through the first spindle (8-4); the speed-adjusting handle assembly further includes a speed-adjusting handle spindle (7-5), an axle sleeve (7-6), a handle sleeve (7-7), a button (7-8), a spring (7-9) and a stop block (7-10); one end of the handle shell (7-1) is fixedly connected with the stop block (7-10), the handle sleeve (7-7) abuts against a stepped face of the stop block (7-10), the speed-adjusting handle spindle (7-5) is arranged in the handle shell (7-1) and connected with the handle shell (7-1) in a rotation manner, one end of the speed-adjusting handle spindle (7-5) is inserted into one end of the axle sleeve (7-6) and connected with the axle sleeve (7-6) through a first pin (7-11), the other end of the axle sleeve (7-6) is fixedly connected with the button (7-8), the axle sleeve (7-6) is connected with the stop block (7-10) in a rotation manner, and the axle sleeve (7-6) is connected with the handle sleeve (7-7) through a second pin (7-14); a potentiometer adjusting pole axle hole (7-5-1) is defined on the other end of the speed-adjusting handle spindle (7-5), an adjusting pole of the potentiometer (7-2) is inserted into the potentiometer adjusting pole axle hole (7-5-1) of the speed-adjusting handle spindle (7-5), the spring (7-9) is sleeved at the periphery of the speed-adjusting handle spindle (7-5), and one end of the spring (7-9) abuts against an axle bumper (7-5-2) on the speed-adjusting handle spindle (7-5) or a collar arranged on the speed-adjusting handle spindle (7-5), and the other end abuts against one end of the axle sleeve (7-6); a radial limit slot (7-10-1) and an axial stop projection (7-10-2) are defined on an end surface of one end of the stop block (7-10), the first pin (7-11) abuts against the limit slot (7-10-1) of the stop block (7-10), the handle sleeve (7-7) is rotated after the button (7-8) is pushed, and the first pin (7-11) is disengaged from the limit slot (7-10-1) of the stop block (7-10) and can abut against the stop projection (7-10-2). <EOS>