Use a vacuum cleaner to suck out the pollen attached to the clothes. Cut off a piece of tape and pat the remaining pollen on the clothes to stick together. If the stain is still there, soak the clothes in cold water and gently wipe it from the back of the stain.
Bleaching may be the only way to remove pollen stains from clothing fibers. On the premise that the clothing fiber can bear it, soak it in water with chlorine bleach for 15 minutes, then wash it with clear water and then wash it in the usual way.
Pollen belongs to plants, so it is alkaline and neutralized with acid. Soak the dirty place in warm water, wash it yellow with oxalic acid, and then wash it again with laundry detergent.