The present invention discloses a rubidium atom frequency standard digital phase locked frequency multiplier. The input terminal of the digital phase locked loop is connected with the output terminal of the rubidium atom frequency standard 10MHz voltage control crystal oscillatory as the output terminal of the frequency multiplier. The output terminal of the digital phase locked loop is connected with the output terminal of the microwave oven amplifier which is connected with the output terminal of the step matching circuit. The output terminal of the step matching circuit as the output terminal of the frequency multiplier is connected with the input terminal of the rubidium atom frequency standard microwave cavity. The phase detector and the digital frequency synthesizer are integrated by a chip AD 9956. The rubidium atom frequency standard digital phase locked frequency multiplier provided by the present invention adopts digital synthesizer as the fractional divider in which a digital phase locked loop is inserted, sets and modulate the fractional frequency division ratio of the digital synthesizer through the single chip computer MSP430F169 thus enabling the direct fractional frequency multiplying and frequency modulation of the frequency multiplier. The present invention with a simple structure, high degree of integration, high purity of the spectrum, low phase noise, small stray and high degree of digitalization is easy to modulate and can be used to produce miniaturized rubidium atom frequency standard.