Signal　generator　used　widely　in　circuit　experiment　is　either　expensive　or　not　satisfying　the　requirements　as　high-frequency　precision　function　signal　sources.　A　high　frequency　signal　generator　with　precision　function　is　proposed,　which　is　controlled　by　MAX038　and　single-chip　microcontroller.　The　signal　generator　is　able　to　generate　four　kinds　of　signals　as　triangle　wave,　square　wave,　sine　wave　and　PWM　signals,　using　method　of　reduced　frequency　range　of　the　largest　fine-tune　in　order　to　reduce　the　maximum　output　frequency　distortion　rate　while　reducing　the　high-resolution　adjustment　requirement　of　DAC.　This　signal　generator　compared　with　commonly　used　high-resolution　DAC　and　precision　adjustment　function　signal　generator　has　some　advantages　of　the　low　cost　and　so　on.