Digital microfluidic biochips in the process of biochemistry analysis has good promising applications

but cross-contamination will occur in detection process. In order to ensure the precision of complex biochemical experimental analysis results

the contamination should be cleaned. Contamination removal strategy based on maxmin ant colony algorithm is proposed to realize optimizing wash droplets route. Establishing multiple travelling salesman problem（ MTSP） model for digital microfluidic biochips contamination

establishing tabu judgement strategy based on fluid and time constraints and selection strategy of ant colony algorithm to achieve the purpose of optimizing the path planning of wash droplet and cleaning up contamination. Experimental results show that the scheme can reduce the time of clearning contamination and number of used array cells effectively.