A printing device, comprising a main control board, a resin vat, a vibration generating assembly, a detection assembly and a support plate, wherein the resin vat is configured for containing a liquid to be detected; wherein the vibration generating assembly comprises a drive component and a paddle, wherein a drive end of the drive component is connected to the paddle, and the drive end is configured to drive the paddle to vibrate; and a first end of the paddle is arranged on a first face of the support plate, and a second end of the paddle extends into the liquid to be detected, wherein the first end of the paddle and the second end of the paddle are two opposite ends of the paddle, and the first face of the support plate faces to the liquid to be detected; wherein the detection assembly comprises an elastic sheet, a resistance strain gage and a detection circuit, wherein the resistance strain gage is attached to the elastic sheet; a first end of the elastic sheet is arranged on the first face of the support plate, and a second end of the elastic sheet extends into the liquid to be detected, wherein the first end of the elastic sheet and the second end of the elastic sheet are two opposite ends of the elastic sheet; and the elastic sheet is configured to change a resistance value of the resistance strain gage according to a deformation of the elastic sheet caused by vibration of the liquid to be detected; wherein a first end of the detection circuit is electrically connected to the resistance strain gage, a second end of the detection circuit is connected to the main control board; the detection circuit is configured to determine an output voltage according to the resistance value of the resistance strain gage, wherein the main control board determines a depth of the liquid to be detected according to the output voltage. wherein the vibration generating assembly comprises a drive component and a paddle, wherein a drive end of the drive component is connected to the paddle, and the drive end is configured to drive the paddle to vibrate; and a first end of the paddle is arranged on a first face of the support plate, and a second end of the paddle extends into the liquid to be detected, wherein the first end of the paddle and the second end of the paddle are two opposite ends of the paddle, and the first face of the support plate faces to the liquid to be detected; a drive end of the drive component is connected to the paddle, and the drive end is configured to drive the paddle to vibrate; and a first end of the paddle is arranged on a first face of the support plate, and a second end of the paddle extends into the liquid to be detected, wherein the first end of the paddle and the second end of the paddle are two opposite ends of the paddle, and the first face of the support plate faces to the liquid to be detected; wherein the detection assembly comprises an elastic sheet, a resistance strain gage and a detection circuit, wherein the resistance strain gage is attached to the elastic sheet; a first end of the elastic sheet is arranged on the first face of the support plate, and a second end of the elastic sheet extends into the liquid to be detected, wherein the first end of the elastic sheet and the second end of the elastic sheet are two opposite ends of the elastic sheet; and the elastic sheet is configured to change a resistance value of the resistance strain gage according to a deformation of the elastic sheet caused by vibration of the liquid to be detected; the resistance strain gage is attached to the elastic sheet; a first end of the elastic sheet is arranged on the first face of the support plate, and a second end of the elastic sheet extends into the liquid to be detected, wherein the first end of the elastic sheet and the second end of the elastic sheet are two opposite ends of the elastic sheet; and the elastic sheet is configured to change a resistance value of the resistance strain gage according to a deformation of the elastic sheet caused by vibration of the liquid to be detected; wherein a first end of the detection circuit is electrically connected to the resistance strain gage, a second end of the detection circuit is connected to the main control board; the detection circuit is configured to determine an output voltage according to the resistance value of the resistance strain gage, wherein the main control board determines a depth of the liquid to be detected according to the output voltage.