A tubeless fluid delivery device comprising: a controller , comprising a first housing which has a first built-in circuit, wherein the first housing is provided with a first engagement part and a first insertion part electrically connected to the first built-in circuit; and a pump base combined with the controller , which comprises a second housing having a second built-in circuit, a reservoir, a piston, a push rod, a driving member and a battery, wherein the second housing is provided with a second engagement part correspondingly engaged with the first engagement part and a second insertion part electrically connected to the second built-in circuit, wherein the second insertion part is correspondingly inserted in the first insertion part to realize electrical connection between the first built-in circuit and the second built-in circuit; characterized in that the second engagement part is connected to a clamping hook handle , a gap is formed between an inner side of the clamping hook handle and a bottom shell of the pump base , wherein when the clamping hook handle is pressed, the clamping hook handle pushes the second engagement part and disengages it from the first engagement part ; in that the first insertion part is a sealed socket, the sealed socket is provided with a groove in which a connector configured to be electrically connected to the first built-in circuit is disposed, wherein an O-shaped sealing ring is set on a surface on which the connector is attached with the sealed socket; and in that the second insertion part is a plug which comprises a plug body circumferentially set with an O-shaped sealing ring and a bolt embedded in the plug body ; wherein the bolt is a wedge structure; and wherein when the plug is inserted into the sealed socket, the bolt is inserted into the connector and is electrically connected to the connector , wherein the O-shaped sealing ring on the plug body and the sealed socket fit tightly to achieve water proof sealing. a controller , comprising a first housing which has a first built-in circuit, wherein the first housing is provided with a first engagement part and a first insertion part electrically connected to the first built-in circuit; and a pump base combined with the controller , which comprises a second housing having a second built-in circuit, a reservoir, a piston, a push rod, a driving member and a battery, wherein the second housing is provided with a second engagement part correspondingly engaged with the first engagement part and a second insertion part electrically connected to the second built-in circuit, wherein the second insertion part is correspondingly inserted in the first insertion part to realize electrical connection between the first built-in circuit and the second built-in circuit; characterized in that the second engagement part is connected to a clamping hook handle , a gap is formed between an inner side of the clamping hook handle and a bottom shell of the pump base , wherein when the clamping hook handle is pressed, the clamping hook handle pushes the second engagement part and disengages it from the first engagement part ; in that the first insertion part is a sealed socket, the sealed socket is provided with a groove in which a connector configured to be electrically connected to the first built-in circuit is disposed, wherein an O-shaped sealing ring is set on a surface on which the connector is attached with the sealed socket; and in that the second insertion part is a plug which comprises a plug body circumferentially set with an O-shaped sealing ring and a bolt embedded in the plug body ; wherein the bolt is a wedge structure; and wherein when the plug is inserted into the sealed socket, the bolt is inserted into the connector and is electrically connected to the connector , wherein the O-shaped sealing ring on the plug body and the sealed socket fit tightly to achieve water proof sealing. <EOS>