Abstract: A method for adjusting height of a 3d printer nozzle. In an embodiment, the method uses a fully wavy line as a reference line. The method includes the following steps. Determining an initial value of a height difference between the nozzle and a bottom of a probe by using a feeler gauge. Moving the nozzle vertically to adjust the height based on the initial value, obtaining a printing height of a first line, and printing the first line. Determining whether the first line is a fully wavy line. Adjusting the height of the nozzle for N times according to a preset step value, and printing N lines with corresponding heights. Determining whether the N lines have a fully wavy line. Calculating the height difference between the nozzle and the bottom of the probe by an equation. Adjusting the height of the nozzle.