The invention discloses a method for separating and purifying zymolytic spherical nanocellulose. The method comprises the steps that an eucalyptus pulp board is subjected to beating, swelling and other pretreatment, and crude spherical nanocellulose is obtained through composite enzymatic hydrolysis of high-concentration cellulase and xylanase, wherein the enzymatic hydrolysis temperature is 30-55DEG C, the enzymatic hydrolysis time is 5-10 hours, and the total concentration of the enzyme activity is 200-500 u/mL; diluted acid is added, and flocculation and centrifugation are carried out, sothat reducing sugar and soluble protein are separated from the spherical nanocellulose; acid is added into centrifuged precipitates for flocculation, ultrasonic treatment and centrifugation; finally,the nanocellulose and insoluble protein are dispersed into distilled water, ultrasonic treatment and centrifugation are carried out, and supernatant is the purified spherical nanocellulose. The purityof the prepared spherical nanocellulose is 99.99% or above, the diameter range is 15-40 nanometers, and the heat stability is better. The adopted method for purifying the spherical nanocellulose through composite enzymatic hydrolysis, diluted acid flocculation and washing has the advantages that the time is short, the efficiency is high, and the process is green and environmentally friendly.