The invention discloses a preparation method of a multipurpose compound photocatalytic biological cell vector. The method comprises the following steps: treating Escherichia coli with Escherichia coli T-even phage to allow a vacant shell of Escherichia coli to be left; carrying out ultrasonic washing on the vacant shell of Escherichia coli with absolute ethanol, citric acid, and distilled water, immersing the vacant shell of Escherichia coli into a deposition reaction solution, putting the deposition reaction solution in a microwave oven, and irradiating for 5-10min at a power of 300W; and taking out, fully washing with distilled water until no obvious TiO2 shedding, and carrying out natural air drying to obtain the multipurpose compound photocatalytic biological cell vector. The method of the invention which is simple and easy to operate and adopts common chemical and biological materials as raw materials has the advantages of convenient production and wide suitableness, is suitable for suspended vectors with photocatalytic functions of bubbleless biological aerated filters and can satisfy suspended vectors in compound membrane bioreactors.