The utility model discloses a field output anti-neck-cutting protection circuit, which comprises a relay K, a resistor R1, an inductor L1, an optocoupler U1, a unidirectional silicon controlled rectifier VS and an optocoupler U2. The field output anti-neck-cutting protection circuit provided by the utility model avoids neck-cutting phenomenon of a CRT kinescope caused by failure of a field output circuit, a detection end is isolated through the optocouplers, input impedance of a sampling circuit is very high and is several ten times that of a field deflection coil, the field output anti-neck-cutting protection circuit cannot cause any interference to the original machine, and is suitable for additional installation of any CRT color television.