The paper presents a design of electronic cipher lock based on touch screen,which takes microprocessor LPC2132 of ARM7 as the core component to control the entire system.The paper makes detailed description about the design principle both of hardware and software.The system has some functions:password input,add,clear and display,when password is correct the system is unlock.Alarm when entering wrong password over three times,lock the keyboard and set the initial system when the input password is wrong or the input time is over.This design reduces the fault rate and improves the reliability,security and safety.Combined with touch screen,the electronic cipher lock works effectively and conveniently.