The utility model discloses a metal nanoparticles carbon nanotube titanium dioxide catalyst's preparation facilities, including plasma power supply, gas cylinder and plasma reactor, plasma reactor includes: relative telluric electricity field and the high voltage electrode who sets up, high voltage electrode connects plasma power supply, and locate quartz glass reactor and the quartz glass board between telluric electricity field and the high voltage electrode, the quartz glass reactor is connected the gas cylinder. The utility model discloses a device using plasma technique is to decorationsof modify of tiO2 electrode, and the metal nanoparticles MWNTsTiO2 electrode that obtains is prepared to realization metal particles MWNTs guidance quality growth course.