The invention provides a portable electric insect sucking device and an insect sucking method therefor. The portable electric insect sucking device comprises an insect sucking tube and a separator, wherein the insect sucking tube is used for sucking insects, and the separator is used for achieving insect collecting; an exhaust tube, which communicates with the insect sucking tube and is used for enabling the insect sucking tube to generate negative pressure, is detachably connected with the base of the insect sucking tube, an insect sucking port which is used for sucking the insects is formedin the end part of the insect sucking tube, the exhaust tube communicates with a negative-pressure device so as to enable the insect sucking tube to generate negative pressure and collect the insects,and a filter screen, which is used for isolating the insects and preventing the insects from entering the exhaust tube from the insect sucking tube, is arranged between the exhaust tube and the insect sucking tube. The insect sucking device provided by the embodiments is simple in structure, easy to assemble and disassemble, low in cost and convenient in operation and is particularly applicable to the extensive, efficient, non-destructive collecting and separating of target insects.