This chapter presents a thorough introduction to wash-and-sweep street sweepers, encompassing their main features, types, applications, and prospects for future development. First, the chapter outlines the core characteristics and usage scenarios of wash-and-sweep street sweepers, supported by illustrations. Second, it details the major components and structural layout of these vehicles. Third, the chapter discusses key design fundamentals, including parameter determination, chassis selection, and powertrain design. Fourth, the major systems and parts—such as the water tank and wastewater tank, waterway system, cleaning device, pneumatic conveying system, hydraulic and pneumatic system, and control system—are systematically examined. Fifth, technical specifications, performance tests, inspection criteria, and noise measurement methods are introduced to ensure operational excellence. Finally, the chapter provides guidance on selecting suitable wash-and-sweep street sweepers and presents the main technical parameters for reference.