A swing unit for construction equipment, comprising: a swing motor; a swing reducer connected to the swing motor; a parking brake device disposed between the swing motor and the swing reducer to constrain rotation of the swing reducer, separately from the swing motor; a coupler connecting an output shaft of the swing motor and an input shaft of the swing reducer; a plurality of brake discs fitted to outer circumferential surfaces of the coupler to rotate at a same speed as a rotating speed of the coupler and be able to perform translation in an axial direction of the coupler; and a plurality of friction discs alternating with plurality of brake discs, wherein the parking brake device comprises: a housing surrounding an outer circumference of the coupler while being spaced apart from the outer circumference of the coupler; at least one hydraulic port provided in a side portion of the housing to provide a path through which working fluid is introduced into the housing; a brake piston fitted to an inner portion of the housing, wherein the brake piston generates axial displacement in response to the working fluid and squeezes the plurality of brake discs and the plurality of friction discs or releases squeezing of the plurality of brake discs and the plurality of friction discs; a return spring connected to one longitudinal end of the brake piston to elastically support the brake piston; and a manual release portion, characterized in that the manual release portion comprises: a recess provided in an outer circumferential surface of the brake piston facing a wall of the housing, and having an inclined surface; a hole provided in the wall of the housing that the recess faces; and a set screw having a head conforming to the recess, wherein the head is fitted into the recess by screw engagement of the set screw with the hole. a swing motor; a swing reducer connected to the swing motor; a parking brake device disposed between the swing motor and the swing reducer to constrain rotation of the swing reducer, separately from the swing motor; a coupler connecting an output shaft of the swing motor and an input shaft of the swing reducer; a plurality of brake discs fitted to outer circumferential surfaces of the coupler to rotate at a same speed as a rotating speed of the coupler and be able to perform translation in an axial direction of the coupler; and a plurality of friction discs alternating with plurality of brake discs, wherein the parking brake device comprises: a housing surrounding an outer circumference of the coupler while being spaced apart from the outer circumference of the coupler; at least one hydraulic port provided in a side portion of the housing to provide a path through which working fluid is introduced into the housing; a brake piston fitted to an inner portion of the housing, wherein the brake piston generates axial displacement in response to the working fluid and squeezes the plurality of brake discs and the plurality of friction discs or releases squeezing of the plurality of brake discs and the plurality of friction discs; a return spring connected to one longitudinal end of the brake piston to elastically support the brake piston; and a manual release portion, a housing surrounding an outer circumference of the coupler while being spaced apart from the outer circumference of the coupler; at least one hydraulic port provided in a side portion of the housing to provide a path through which working fluid is introduced into the housing; a brake piston fitted to an inner portion of the housing, wherein the brake piston generates axial displacement in response to the working fluid and squeezes the plurality of brake discs and the plurality of friction discs or releases squeezing of the plurality of brake discs and the plurality of friction discs; a return spring connected to one longitudinal end of the brake piston to elastically support the brake piston; and a manual release portion, characterized in that the manual release portion comprises: a recess provided in an outer circumferential surface of the brake piston facing a wall of the housing, and having an inclined surface; a hole provided in the wall of the housing that the recess faces; and a set screw having a head conforming to the recess, wherein the head is fitted into the recess by screw engagement of the set screw with the hole. a recess provided in an outer circumferential surface of the brake piston facing a wall of the housing, and having an inclined surface; a hole provided in the wall of the housing that the recess faces; and a set screw having a head conforming to the recess, wherein the head is fitted into the recess by screw engagement of the set screw with the hole.