The invention discloses a machining method for a eucalyptus core board. The method comprises the following steps that A, a eucalyptus core strip is machined into eucalyptus core small square strips; B, the eucalyptus core small square strips are coated with glue; C, the eucalyptus core small square strips are spliced and then conveyed to a board pressing machine to be pressed and bonded into a board core board blank; D, the board core board blank is subjected to sanding treatment; E, the board core board blank obtained after sanding treatment is subjected to cold pressing through a cold pressmachine, and a formed board blank is obtained; F, the formed board blank is repaired; G, the repaired formed board blank is subjected to hot press treatment; H, the repaired formed board blank is subjected to ash scraping treatment; I, the formed board blank obtained after ash scraping treatment is subjected to secondary sanding treatment; J, the formed board blank obtained after secondary sandingtreatment is subjected to face-skin bonding treatment; K, the formed board blank obtained after face-skin bonding treatment is subjected to secondary hot press treatment; and L, the formed board blank is subjected to edge sawing and polishing. Compared with the prior art, eucalyptus core bars are machined into the eucalyptus core board, energy is saved, and the production cost is reduced.