The invention discloses a cutting quality evaluation method and device based on sugarcane harvesting machine cutter head vibration. The method comprises the following steps that multiple sampling times t are set, and rotating speeds of a cutter head of a sugarcane harvesting machine in different sampling times t are set to be different; multiple vibration displacement data of the cutter head during sugarcane cutting in the sampling times t are collected in real time through a laser displacement sensor, and multiple vibration peak values h of the cutter head are obtained according to the vibration displacement data; evaluation parameters of the parts, left in soil, of cut sugarcane in all the sampling times t are collected, and multiple first comprehensive scores Y of the part, left in the soil, of the cut sugarcane are obtained according to the evaluation parameters; a cutting quality evaluation curve is obtained according to the vibration peak values h and the corresponding first comprehensive scores Y; evaluation indexes of the sugarcane cutting quality are obtained according to the cutting quality evaluation curve. According to the cutting quality evaluation method and device based on sugarcane harvesting machine cutter head vibration, real-time online evaluation on the cutting quality is achieved, and a large quantity of reference data is provided for sugarcane harvesting machine maintenance and farmer planting.