The invention discloses a preparation method for a composite micro-sphere for stopping bleeding in clinical operation. The preparation method for the composite micro-sphere for stopping bleeding in the clinical operation mainly includes that adding water to a crosslinked chitosan wet micro-sphere to prepare into crosslinked chitosan wet micro-sphere solution with concentration 1.5-2.5% (W/V), adding water to a crosslinked starch micro-sphere to prepare into crosslinked starch micro-sphere solution with concentration 10-20% (W/V), mixing according to the volume ratio of 5: 5, 6: 4, 7: 3 or 8: 2, using ultrasonic wave to enable the solution to mix uniformly, using a high-speed centrifugal machine to centrifuge for 30 minutes, defoaming, solidifying in NaOH solution with mass concentration 0.5% under aseptic condition, using alcohol to dehydrate, using injection water to wash, drying at 30 to 40 degrees centigrade to realize a semi-dry state, dehydrating, washing, solidifying, spraying and drying, and packaging and sterilizing through cobalt 60 to obtain the composite micro-sphere for stopping bleeding. The average diameter of the composite micro-sphere for stopping bleeding is 600 to 900 micrometers, the average pore size is 50 to 100 micrometers, and the specific surface area arrives at 720.8-810.2 m2.g -1; the composite micro-sphere for stopping bleeding is capable of absorbing and degrading biological material and stopping the bleeding of various wound and the acute wound bleeding regions of fresh operation tissues.