The article discusses issues of ensuring effective and reliable measurement and control of drill string vibration. A system for active measurement and control of drill string vibration is presented. The system combines both wellhead equipment elements and downhole equipment. At that, there is a specially designed hydromechanical extensional vibration sensor used in wells. The wellhead equipment includes elements of record and analysis of obtained data about drill string vibration. Moreover, the system includes wellhead equipment for stopping vibration. The article analyses optimal parameters for the shape of the hydromechanical vibration sensor. Its optimal shape is established.