Abstract: The single-chip microcomputer as the core is introduced,the reconstruction design of DS18B20 di ital temperature sensor thermocouple is used to calibration experiment instrument. The design reforms the tradition mode of temperature control. The single- chip microcomputer and relay simulation of pulse width modulatic （PWM） is used to realize the intelligent temperature control, improving the precision of temperature control an reach thermal equilibrium speed.

Key words: DS18B20, thermal inertia, pulse width modulation （ PWM ）.