The invention relates to a process for co-producing bio-oil and biological carbon by utilizing 
crop straws, comprising the following steps of: firstly, selecting alkali earth 
metal halides or alkali as molten salts, and putting the molten salts into a 
molten salt thermal pyrolysis reactor; secondly, opening an electrothermal furnace of the 
molten salt thermal pyrolysis reactor; thirdly, sending the 
crop straws into the 
molten salt thermal pyrolysis reactor; fourthly, obtaining a 
liquid product, i.e. the bio-oil by condensing a steam part generated by thermal 
pyrolysis in the molten salt thermal 
pyrolysis reactor, wherein a non-condensation part is a gaseous product; fifthly, regulating the temperature of the molten salt thermal 
pyrolysis reactor to the 
activation temperature, and cooling the molten salt thermal pyrolysis reactor to the 
room temperature after activation is finished; and sixthly, taking out a 
solid product after activation, soaking the 
solid product by using 3mol / L hot 
hydrochloride, and obtaining a 
solid-state product, i.e. the biological carbon by soaking the 
solid product by hot 
distilled water. The invention also provides a special device for co-producing the bio-oil and the biological carbon by utilizing 
crop straws. The invention has simple components and lowers the production cost.