The invention discloses a mixer for a construction site and a work method of the mixer for the construction site. The mixer for the construction site comprises a machine body. A motor is fixedly connected with the upper end of the machine body. The outer side of the motor is provided with a dustproof cover. The lower end of the motor is fixedly connected with a rotating shaft. Mixing blades are fixedly connected with the middle portion of the rotating shaft. The lower end of the rotating shaft is fixedly connected with a rotating disk. A through hole is formed at the lowest position on the upper surface of the rotating disk. A brush is fixedly connected with the center of the lower end of the rotating disk. The upper end of the left side of the machine body is provided with a feeding device. A water inlet hole is formed in the right side of the machine body. The water inlet hole is fixedly connected with a water plug. The center of the lower end face of the machine body is provided with a discharging opening. The discharging opening is fixedly connected with an output plug. The lower end of the machine body is fixedly provided with a self-locking trundle. The mixer for the construction site has good seal performance and is free of dust, low in noise, even in stirring, convenient and rapid to transport, simple in structure and good in work stability.