在“模拟电子技术基础”课程中,图解法可用来分析放大电路的Q点位置、最大不失真输出电压和失真情况等[1]。在实际应用过程中,学生往往对负载线,特别是对交流负载线时容易产生问题,不能在输出特性曲线中正确地画出交流负载线。从而导致对放大电路失真问题分析的错误。文献[1]给出了直流负载线的数学方程,但交流负载线是采用通过Q点做一条斜率为 In the “Analog Electronic Technology Foundation” course, the graphic method can be used to analyze the Q point position of the amplifier circuit, the maximum undistorted output voltage and distortion [1]. In practical applications, students tend to have problems with the load lines, especially with AC load lines. They can not correctly draw the AC load lines in the output characteristics curve. Which led to the analysis of the distortion of the amplifier circuit error. Literature [1] gives the mathematical equation of the DC load line, but the AC load line is made by using Q point to make a slope of