The invention discloses a fungi strain LP-20 (trichoderma spirale) capable of removing or recovering cadmium ion in water, an isolation medium thereof, fungicide containing the fungi strain LP-20, a preparation method of the fungicide, a cadmium ion treatment agent containing the fungi strain LP-20 and a treatment method for the cadmium-containing waste water. The fungi strain LP-20 can tolerate high-concentration cadmium ions in a water solution, can eliminate or recover the cadmium ions in the waste water, is low in cost, convenient in mass production and convenient for realization of industrialization and different downstream applications.