在近场扫描光学显微镜（ＮＳＯＭ）［１］中，近场距离控制一般采用切向力控制法。检测切向力有两种方法：光学检测法和非光学检测法。目前普遍采用非光学检测法，基本上是采用压电陶瓷管控制探针和样品的距离。本文提出一种新的切向力检测系统，利用双压电片实现近场距离控制。实验结果表明，检测灵敏度大大提高，扫描力显微（ＳＦＭ）像的分辨率可达纳米量级。 Near-field scanning optical microscopy (NSOM) [1], near-field distance control generally use the tangential force control method. Tensile force detection in two ways: optical detection and non-optical detection. Currently widely used non-optical detection method, the piezoelectric ceramic tube is basically used to control the distance between the probe and the sample. This paper presents a new tangential force detection system, the use of dual piezoelectric films to achieve near-field distance control. The experimental results show that the detection sensitivity is greatly improved, and the resolution of scanning force microscopy (SFM) images can reach the order of nanometers.