A liquid crystal lens light splitting device (100) and a manufacturing method thereof, and a stereoscopic display device are disclosed. The liquid crystal lens light splitting device (100) is configured to be disposed on a display panel (200) and includes: a first substrate (110), and a second substrate (120) disposed on a light outgoing side of the display panel (200), wherein liquid crystal (150) is filled between the first substrate (110) and the second substrate (120), and a support (130) is provided between the first substrate (110) and the second substrate (120), and wherein the support (130) is opposite to a non-light-outgoing area (201) on the display panel in a light outgoing direction of the display panel (200). The liquid crystal lens light splitting device (100) can mitigate or eliminate crosstalk phenomenon and be used for manufacturing a display device.