A laser Doppler vibrometer can measure the surface velocity of a point on a structure. A continuously scanning laser Doppler vibrometer (CSLDV) was developed to significantly improve efficiency and spatial resolution of vibration measurement of the structure. As a non-contact system, it can avoid the mass-loading problem in vibration measurement using accelerometers. The CSLDV was made by adding two orthogonal scan mirrors in front of a single-point laser Doppler vibrometer. Two scan mirrors can be referred to as X and Y mirrors based on their rotation axes, respectively. During CSLDV measurement, two scan mirrors can be controlled to continuously rotate about their rotation axes, and the laser spot of the CSLDV can continuously move along a pre-designed scan trajectory on the structure, which is a major difference compared to a conventional scanning laser Doppler vibrometer (SLDV) system that has a point-by-point scanning capability. This tutorial first overviews principles in vibration measurement using a CSDLV, such as signal processing methods for structures under various excitations such as sinusoidal, impact, and random excitations, and scan trajectory design methods for structures with various shapes. Recent developments on (1) a novel general-purpose three-dimensional (3D) CSLDV system for measuring 3D full-field vibration of a structure with arbitrarily curved surfaces and (2) a novel zero-contact image-based tracking CSLDV system for measuring vibration of a rotating structure are presented. The general-purpose 3D CSLDV system can measure vibrations of difficult to access areas of structures with the assistance of reflective mirrors and obtain their 3D panoramic modal parameters through a novel vibration stitching method. The image-based tracking CSLDV system can track and scan a rotating structure such as a rotating wind turbine blade through a novel edge detection method and estimate its modal parameters through an improved lifting method and an improved demodulation method. Applications of continuous scanning laser vibrometry to structural damage detection will be discussed.