A new type of fluidized bed system, in which a plasma flow jet was used as the major heating source and the electro-thermal as heat preservation, was developed, tested and improved according to a series of experiments. A two-step pulverized biomass feeder was designed to maintain feeding uniformly. The minimum fluidizing velocity and operating fluidizing velocity were obtained by experiments at cooling conditions. The studies on corn stalk showed that the feeding velocity and temperature had impacts on the yields of bio-oil which grew with the increasing of feeding velocity and went up at first and then declined with the temperature rising. The bio-oil yield occurred at about 477℃.