In order to solve the problem of low accuracy and poor repeatability caused by temperature change when LIBS technology is applied to the analysis of metallurgical process composition, the influence of temperature change on plasma is studied in this paper. The results show that the intensity of the characteristic lines of Al increases with the increase of temperature and reaches saturation at 700 ℃. When the temperature rises to 700, 500 and 200 ℃, Al I increases When the sample temperature is 700 ℃, the plasma electron temperature rises to 13122 K, and the electron density increases to 4.65×10¹⁶ cm^-3 respectively. In the first stage, the sample stops heating and naturally cools down, and the plasma parameters drop rapidly with the sample temperature; in the second stage, when the sample temperature drops to about 660 ℃, the spectral intensity decreases slowly and becomes stable. At this time, the plasma electron The temperature was stable at about 16 000 K, and the electron density was 7.6×10¹⁶ cm^-3; in the third stage, the plasma characteristic parameters continued to decrease until the sample temperature dropped to room temperature. When LIBS technology is applied to the detection of molten metal components, the best measurement point can be obtained by controlling the sample temperature, there by improving the detection accuracy of LIBS technology.