Abstract: Muscular calf vein thrombosis (MCVT) is the common site of deep vein thrombosis (DVT) in the lower extremities. Researchers have found that MCVT can progress to the proximal deep vein and cause more severe DVT in lower limbs, or thrombus detachment can lead to secondary pulmonary thromboembolism (PTE) and even sudden death. This paper mainly explored the incidence of MCVT complicated with PTE, the possible anatomical factors related to MCVT and PTE, the influencing factors of MCVT complicated with PTE, and the current status of risk assessment of PTE in MCVT patients, in order to provide reference for early identification of high risk of PTE and guidance for personalized clinical decision-making in MCVT patients.