A preparation method for a non-spherical hydrogel microparticle embolic agent is provided. The method includes: alternately injecting a oil phase solution and an aqeuous phase solution into an elongated channel, the aqueous phase solution contains a water-soluble polymer to be cross-linked, the aqueous phase solution has a cross-linking reaction in the elongated channel to obtain a product, which is then discharged from the elongated channel to obtain the non-spherical hydrogel microparticle embolic agent. This preparation method is simple in process, and the non-spherical hydrogel microparticle embolic agent obtained from this method has good embolization performance.