The paper designs a signlephase electric ACDC conversion，with controller chip TMS320F28335，active power factor controller UCC28019 as a core of the system，The power factor measurement circuit,output over protection circuit，power factor adjustment circuit were designed.Test results show that when input AC voltage is 24 V and output current is 2 A,the system can output 36 V voltage stably.Its load regulation rate less than or equal to 05%，when input AC voltage from 20 to 30 V,Voltage regulation rate SUis not more than 0.5%,the maximum error of power factor is 0.03，System have overcurrent protection function，overcurrent protection operating is 2.52 A, power factor is up to 0.99.