The invention belongs to the technical field of medicines, and relates to testosterone undecanoate suspension, a preparation method thereof and an application, in particular to testosterone undecanoate suspension which comprises testosterone undecanoate, stabilizers and water. The content of the testosterone undecanoate is 10%-50%, the particle diameter D10 of the testosterone undecanoate is 0.2-0.5 micrometer, the particle diameter D50 of the testosterone undecanoate is 0.5-1.5 micrometers, the particle diameter D90 of the testosterone undecanoate is 2.2-6.0 micrometers, the stabilizers include first stabilizers and second stabilizers, the weight ratio of the first stabilizers to the second stabilizers is (1-10):(1-20), and the weight ratio of the testosterone undecanoate to the stabilizers is (1-20):(1-20). The testosterone undecanoate suspension is good in stability and high bioavailability and low in irritation, redissolved conditions after sedimentation are good, and in-vivo hormone level can be stably maintained for a long time.