The invention relates to a twice time limit checking anti-theft method. When user enters into the anti-theft area, user should input the relative information to do the twice time limit checking, the time limit of each checking is in 3-50s, if it can't pass the checking during the time limit, it enters into the alarm anti-theft condition; it adopts camera CCD to real-time record the operating image data of the anti-theft area and stores the image data in the inner U disk to collect, delete and store the image data at the same time. |