The invention discloses a lawn sprinkling device used for a garden. The device includes a base, the top side of the base is provided with an installation groove, the installation groove is internallyand movably provided with a water tank, and the top side of the water tank extends to the outside of the installation groove; the two sides of the installation groove are provided with fixation mechanisms used for fixing the position of the water tank, the two sides of the base are rotatably provided with water connecting pipes, the same water spraying pipe is fixedly connected between the two water connecting pipes, and several nozzles are arranged at equal intervals on the water spraying pipe. The preparation method of the lawn sprinkling device used for the garden includes the following steps that 1, the height of the base is adjusted, a rotary motor is started, an output shaft of the rotary motor drives a rotating shaft to rotate, the rotating shaft drives a gear to rotate, and the gear drives a rack to move up and down. According to the device and the preparation method of the device, a water tank can be steadily installed and disassembled, the height of a slide rod is adjusted, the spray angle of the water spraying pipe is conveniently adjusted, the structure is simple, and the device is convenient to use.