This paper presents a component-based language named CDL (CPS Description Language) to describe Cyber-Physical Systems according to the actor-oriented model. The sensors, actuators and compute components in a Cyber-Physics system are encapsulated into components with uniform abstraction. Therefore, a system description is decomposed into the components contained in the system, the directed relationships between components, and the system constraints. In addition, we design and implement the development tool of CPS based on CDL, which provides the functions of system description generation, verification and installation. At last, two system examples are implemented to prove that the amount of code written by developers could be reduced and the efficiency of programming could be improved to a certain extent by using CDL.