The present invention provides an ultra-microinjection detection and control device based on lensless imaging and a method thereof. A lensless optical liquid level sensor is used to measure a change of a liquid level in an injection needle. A microinjection control unit is used to track the change of the liquid level and correct an injection pressure of the injection pump. Transmitted light generated by a parallel light source passes through a transparent glass tube of the injection needle. Then the transmitted light passes through a light filtering film to reduce the intensity of the parallel light source to a photosensitivity range of a micro linear array image sensor chip. Finally, the transmitted light enters the micro linear array image sensor chip, so that the micro linear array image sensor chip measures the change of the liquid level in the injection needle.