We develop a kind of neutron detector, which consists of a polyethylene thin film and two PIN semicon- ductors connected face-to-face. The detector is insensitive to γ-rays. Its sensitivity to neutron has been calculated with MCNP program and calibrated by experiments, and the results indicate that the neutron sensitivity of the compensa- tion detector will vary with polyethylene converter. The compensation PIN detector can be employed to measure pulse neutron in neutron and gamma mixture radiation field. Its sensitivity to neutron has been calculated with neutron detector, which consists of a polyethylene thin film and two PIN semicon- ductors connected face-to-face. The detector is insensitive to γ-rays. Its sensitivity to neutron has been calculated with MCNP program and calibrated by experiments, and the results that that neutron sensitivity of the compensa- tion detector will vary with polyethylene converter. The compensation PIN detector can be employed to measure pulse neutron in neutron and gamma mixture radiation field.