The invention relates to a preparation method of a 
zinc oxide visible-light-induced photocatalyst sensitized by squarylium 
cyanine. The preparation method comprises the following steps: dissolving Zn(Ac)22H2O and glucose into deionized water; carrying out ultrasonic 
processing to form a settled solution; after transferring the solution into a liner of a 
polytetrafluoroethylene autoclave, performing 
hydrothermal reaction for 12 to 24 hours at a temperature of 140 to 180 DEG C; after cooling to 
room temperature, carrying out centrifugal washing on the obtained black 
powder respectively with the deionized water and absolute ethyl 
alcohol; 
drying at a temperature of 60 DEG C to obtain a 
zinc oxide and carbon composite precursor; placing the precursor into a 
muffle furnace to calcine for 3 hours at a temperature of 400 to 600 DEG C, so as to obtain 
zinc oxide microspheres; mixing the zinc oxide microspheres and the squarylium 
cyanine as well as an 
organic solvent; at a temperature of 30 to 60 DEG C, carrying out ultrasonic 
processing on the mixture for 0.5 to 2 hours; then removing the 
organic solvent under the condition of 
pressure reduction; and finally, 
drying the obtained 
solid at a temperature of 60 DEG C. The zinc oxide visible-light-induced photocatalyst sensitized by the squarylium 
cyanine can be used for 
photocatalysis processing on organic pollutants in air, soil and 
sewage.