The invention discloses a motor for a deep-well pump, and relates to the field of deep-well pumps. The motor comprises a machine cylinder, a front end cover and a rear end cover, wherein a machine shaft is rotationally connected in the machine cylinder, and a mounting cylinder is arranged on the outer side wall of the rear end cover; a mounting tube is arranged in the mounting cylinder, and a mounting plate is arranged on the upper end face of the mounting tube; a balance plate is arranged on the mounting plate, and a plurality of balance grooves are formed in the balance plate; a balance block is embedded in each balance groove; a pressing plate is arranged on the upper end face of the balance block, and the lower end surface of the balance block is provided with a balance ball which abuts against the bottom wall of the corresponding balance groove; and the outer wall of the rear end of the machine shaft is sleeved with a graphite sleeve used for abutting against the upper end face ofthe pressing plate. The motor has the following advantages and effects that: when the machine shaft is stressed, the balance degree of the pressing plate is automatically adjusted through the shakingof the balance block and the balance ball, so that the graphite sleeve can stably abut against the upper end surface of the pressing plate; and the machine shaft is always fixed and rotated at the same position, so that the phenomenon of shaking of the machine shaft is avoided, and the effect of high stability is achieved.