A preparation method of cotton stalk printing paper pulp particularly includes the following steps that firstly, cleaned dry cotton stalks are exploded through a
steam explosion method, and then granules with the average grain
diameter being below 120 micrometers are obtained; secondly, the granules are placed in water,
toluene diisocyanate, insectwax,
glyceride maleic anhydride resin and 1-2 parts by weight of
polyurethane resin are added, temperature rises to the range from 60 DEG C to 80 DEG C, and the mixture is stirred for 1-2 hours; thirdly, water at the temperature
ranging from 35 DEG C to 50 DEG C is added to the mixture obtained through the second step, and meanwhile 2-4 parts by weight of alums are added, the mixture is filtered after being stirred for 15-30 minutes, filter liquor is drained, and filter materials are reserved; fourthly, the filter materials are placed in a reaction kettle,
titanium dioxide with the average grain
diameter being below 10 micrometers, 1-3 parts by weight of
starch, phenolic resin and octyl
alcohol are added, and the mixture is stirred. Paper products prepared through the paper pulp is bright in color, tough and durable, good in printing performance, long in service life, and suitable for large-scale industrial production.