The invention discloses a method, an apparatus, and a monitoring system for acquisition of a machine's rotating speed and vibration data. A machine rotating speed acquisition apparatus according to the inventive disclosure comprises a speed sensor and a controlling unit. The speed sensor is operative to count the pulses triggered during the rotation of the machine so as to acquire the machine's rotating speed. The controlling unit is operative to record the triggering moment of each pulse. Furthermore, each time when a pulse triggering moment is recorded, a rotating speed time scale message containing that pulse triggering moment is broadcasted to at least one machine vibration data acquisition apparatus, in order for the at least one machine vibration data acquisition apparatus to receive that rotating speed time scale message and record the local time when receiving that message.