At present, the impact of oil spill pollution on marine organisms has garnered significant attention, and the current state of nearshore marine areas is increasingly severe. In recent years, the environmental issue of global warming has become increasingly serious, and frequent extreme high-temperature climates are affecting the rise in seawater temperatures. In this study, sea cucumbers were exposed to high temperatures (T = 22 ℃, 24 ℃, 26 ℃, 28 ℃, 30 ℃, 32 ℃, and 34 ℃) and crude oil (WAF dilution ratio = 100%, 80%, 60%, 40%, 20%, 10%, 5%, and 1%) and combined high temperature and crude oil stress (WAF dilution ratio = 60%, T = 22 ℃, 24 ℃, 26 ℃, 28 ℃, and 30 ℃) for 96 h. Based on the changes in sea cucumber mortality, the environmental thresholds for sea cucumbers under high temperature and crude oil stress were determined. The results showed that the effects of the three stresses on sea cucumber mortality were concentration-dependent, and the LC50 values for sea cucumbers under different stresses were LC50(thermal) = 28.32 ℃, LC50(crude oil) = 14.14 mg/L, and LC50(thermal+crude oil) = 28.20 ℃. This study provides valuable reference data for sea cucumber farmers regarding pond water environment early warning values and prevention of related harmful factors, and offers more information for sea cucumber farmers and oil spill emergency plans.