A juicer, comprising: a base defining a receiving cave therein for receiving a cutter and food to be processed; a motor for driving the cutter; a cover fixed on the base, a feed tube extending upwardly from the cover and acting as an entrance for the food; a pusher configured to be inserted into the feed tube to push the food into the receiving cave; a linkage assembly configured at the feed tube; and a trigger assembly connected to the linkage assembly and configured for generating a trigger signal to start the motor; the linkage assembly comprises a pressure component and a follower lever; the pressure component is movably connected to the feed tube and close the opening of the feed tube; the follower lever is rotatably connected to the pressure component, and is movable up and down; the juicer is characterized in that, the trigger assembly comprises two signal generators (311, 312) connected to an end of the follower lever and three inductors (321, 322, 323) configured at the base; at least one weakest area of signal exist between the two signal generators (311, 312), and the three inductors (321, 322, 323) are placed face to face with the two signal generators (311, 312) and the at least one weakest area, respectively; the three inductors (321, 322, 323) are connected electrically with the motor's control circuit; electronic system of the juicer is preset to achieve motor running only when two (321, 322) of the inductors (321, 322, 323) corresponding to the two signal generators (311, 312) detect magnetic force and thus receive signals from the two signal generators (311, 312) while a third of the inductors (321, 322, 323) corresponding to the weakest area does not receive any signal from the weakest area. a base defining a receiving cave therein for receiving a cutter and food to be processed; a motor for driving the cutter; a cover fixed on the base, a feed tube extending upwardly from the cover and acting as an entrance for the food; a pusher configured to be inserted into the feed tube to push the food into the receiving cave; a linkage assembly configured at the feed tube; and a trigger assembly connected to the linkage assembly and configured for generating a trigger signal to start the motor; the linkage assembly comprises a pressure component and a follower lever; the pressure component is movably connected to the feed tube and close the opening of the feed tube; the follower lever is rotatably connected to the pressure component, and is movable up and down; the juicer is characterized in that, the trigger assembly comprises two signal generators (311, 312) connected to an end of the follower lever and three inductors (321, 322, 323) configured at the base; at least one weakest area of signal exist between the two signal generators (311, 312), and the three inductors (321, 322, 323) are placed face to face with the two signal generators (311, 312) and the at least one weakest area, respectively; the three inductors (321, 322, 323) are connected electrically with the motor's control circuit; electronic system of the juicer is preset to achieve motor running only when two (321, 322) of the inductors (321, 322, 323) corresponding to the two signal generators (311, 312) detect magnetic force and thus receive signals from the two signal generators (311, 312) while a third of the inductors (321, 322, 323) corresponding to the weakest area does not receive any signal from the weakest area.