A catheter-free drug fluid infusion device, comprising a controller (11) and a pump (12) combined with the controller (11). The controller (11) comprises a first housing having a first built-in circuit. The first housing is provided with a first engagement portion and a first insertion portion electrically connected to the first built-in circuit. The pump (12) comprises a second housing having a second built-in circuit, a drug storage cylinder, a piston, a push rod, a driving means and a battery. The second housing is provided with a second engagement portion correspondingly engaged with the first engagement portion and a second insertion portion electrically connected to the second built-in circuit. The second insertion portion is correspondingly inserted in the first insertion portion to realize electrical connection between the first built-in circuit and the second built-in circuit. The catheter-free drug fluid infusion device employs a detachable structural design to reduce the cost, so as to solve the problem that a drug fluid infusion device in the prior art has complex operation, large size and high cost.