The invention discloses a signal generation circuit. An operational amplifier and a discrete device are combined to form a square wave-triangular wave generation circuit, and triangular waves are obtained by square waves output by a hysteresis comparator through a comparator. A conversion circuit from the triangular waves to sine waves is mainly completed through a diode and a resistance voltage division circuit. According to the design principle of the conversion circuit, nonlinearity of a transmission characteristic curve of the diode is utilized. Compared with the prior art, the waveform distortion meets the index requirement, the frequency coverage range is large, the frequency is adjustable, output signals are stable and reliable, and the cost of the circuit is low.