The utility model discloses a lock and indoor lighting circuit interlock control circuit has solved the people and has left the problem that the realization lighting circuit of office can reliably cutoff. Switch mechanical connection with knife switch (2) is in the same place including the lock spring bolt, the lambda line wiring end of the switch of knife switch (2) links together with the positive pole of battery (1), the first leading -out terminal (A) and the one end of pilot lamp (3) of knife switch (2) are connected, the other end of pilot lamp (3) links together with the negative poleof battery (1), the second leading -out terminal (B) of knife switch (2) links together with the one end of control coil (4) of relay, the other end of control coil (4) of relay links together with the negative pole of battery (1), it has normally closed contact (6) of relay to establish ties in the supply circuit that indoor lighting alternating current power supply (5) constitutes with indoor lighting (7). Realized the lock and locked the effect that the back power reliably cut off, be particularly suitable for the office space and use.