The invention provides a preparation method of a bone tissue engineering porous ceramics scaffold, belongs to the technical field of medical apparatus and instruments, and is capable of effectively solving the uniform distribution problem of drug carrying chitosan microspheres coating the surface of the bone tissue engineering porous ceramics scaffold. The preparation method comprises the steps of firstly preparing a porous scaffold, then preparing a drug carrying microspheres, and then preparing a ceramics scaffold coated with alginic acid. After obtaining the ceramics scaffold of which the surface is coated with the alginic acid, the drug carrying microspheres is needed to be combined with the ceramics scaffold: uniformly dispersing the prepared drug carrying microspheres into a centrifuge tube filled with deionized water, soaking the ceramics scaffold coated with the alginic acid into the centrifuge tube filled with the drug carrying microspheres, placing at the temperature of 37 DEG C, vibrating in a constant-temperature vibration box with the rotation speed of 60 to 120r/min for 1 to 3h, taking out the ceramics scaffold, repeatedly washing by using the deionized water, and then performing vacuum drying to obtain the bone tissue engineering porous ceramics scaffold which is coated with the alginic acid and provided with the uniformly-distributed drug carrying microspheres. The bone tissue engineering porous ceramics scaffold is mainly used for human bone tissue repair.