The invention relates to a nano spectral analysis and electrochemical analysis technique, and relates to a dark-field nano spectral electrochemical detection pool for plasma observation. The detection pool comprises a quartz glass plate, a circular electrode and a bearing plate which are all transparent structures, wherein a circular electrode fixing pool, a channel, a flowing injection port and an outflow port on the channel, a reference electrode fixing port, a counter electrode fixing port, a deoxygenization space, an inert gas feeding port, a gas extraction port and an electrode lead connection channel are arranged on the quartz glass plate; and the quartz glass plate and the bearing plate are formed into a sandwich layer, the circular electrode is fastened in the electrode fixing pool, and the quartz glass plate and the bearing plate are hermetically fixed by using screws. According to the invention, a light path is easy to calibrate, an operation of deoxygenization is convenient, and a working electrode is easy to install, remove and replace; and the detection pool has spatial discrimination and micro-area analysis capabilities, so that the detection pool can be used as a technique for carrying out observation and acquisition on resonance Rayleigh scattered spectrums of plasmas generated by single nanoparticles and generated by that single nanoparticles and molecules of an interface solution are interacted under the condition of electrochemical control.