The invention discloses a nuclear magnetic resonance supporting device for single oleaginous seed sampling. The nuclear magnetic resonance supporting device is characterized by including a rotary sampling device, a vacuum generator and a computer for nuclear magnetic resonance testing, wherein the rotary sampling device includes a bracket, a rotating disc rotatably installed on the bracket, and a stepping motor connected with the rotating disc and used for driving the rotating disc to rotate; a suction port connected with the vacuum generator is arranged on the rotating disc; a single seed capacity groove capable of only accommodating one seed is arranged on the suction port; and the computer for nuclear magnetic resonance testing is electrically connected with control circuits of the stepping motor and the vacuum generator respectively. The device provided by the invention can be used for sample-taking and sample-placing of single oleaginous seed automatically and accurately, and adjust the speed of sample-taking and sample-placing as per the testing requirement, thereby effectively cooperating with a nuclear magnetic resonance analyzer for the purposes of being automatic, large in scale and quick in seed selection, and greatly improving the testing efficiency.