乳腺癌切线野照射是一常用的放疗技术。在模拟机下定位直观、准确，但一些基层医院尚未购置模拟机。本文介绍脱模画图法设计乳腺切线野投照角度、投照范围的方法。 Tangential field irradiation of breast cancer is a commonly used radiotherapy technique. Under the simulator positioning intuitive and accurate, but some primary hospitals have not yet purchased the simulator. This article describes the demolition drawing method design breast tangent field projection angle, projection method.