The invention discloses a parallel amplitude analyzer of a monocrystal multi-power spectrum. The analyzer comprises a nuclear radiation detector which is used for transmitting nuclear radiation signals to a preamplifier circuit, a preamplifier circuit which transmits the amplified and formed signals to a controllable gain amplifier, a controllable gain amplifier which amplifies the nuclear radiation signals in different times, an A/D converter ADC processing unit which correspondingly convert the nuclear radiation signals amplified in different times, a data transmission module which realizesstorage of spectral line data and access to reading of the spectral line data by means of parallel data transmission and a main controller which controls high-voltage power supply to supply high-voltage power to the nuclear radiation detector, CPLD reset signals and a segment offset address of an external RAM. In the invention, two amplifiers of different amplification times are adopted to amplify the nuclear radiation signals, so that both high-energy and low-energy spectral line data can be obtained and resolution ratio of the system can be improved.