A battery state estimation method, comprising: obtaining (S101, S201) a first cell state parameter of each of a plurality of cells in a battery; under a condition that there are multiple cell partitions in the battery, performing (S102) the following step for each of the cell partitions: determining (S203) whether the first cell state parameter of each cell belonging to a cell partition is within a first cell state parameter range corresponding to the cell partition, wherein the first cell state parameter range is a parameter range in which a deviation of the first state parameter is within a first deviation range; under a condition that the first cell state parameter of each cell in each of the cell partitions is within the first cell state parameter range corresponding to the cell partition, performing (S103) the following step for each of the cell partitions: estimating (S204) a cell state of each of the cell partitions based on a target cell state parameter corresponding to the cell partition, wherein the target cell state parameter is determined based on the first cell state parameter of each cell in each of the cell partitions; under a condition that there are no multiple cell partitions in the battery, partitioning (S207) the cells based on the first cell state parameter of each cell to assign the cells among which a deviation of the first cell state parameter is within the first deviation range to a same cell partition, and performing (S208) the following step for each of the cell partitions: estimating the cell state of each of the cell partitions based on the target cell state parameter corresponding to the cell partition; and estimating (S104, S209) a battery state of the battery based on the cell state of each of the cell partitions in the battery. obtaining (S101, S201) a first cell state parameter of each of a plurality of cells in a battery; under a condition that there are multiple cell partitions in the battery, performing (S102) the following step for each of the cell partitions: determining (S203) whether the first cell state parameter of each cell belonging to a cell partition is within a first cell state parameter range corresponding to the cell partition, wherein the first cell state parameter range is a parameter range in which a deviation of the first state parameter is within a first deviation range; under a condition that the first cell state parameter of each cell in each of the cell partitions is within the first cell state parameter range corresponding to the cell partition, performing (S103) the following step for each of the cell partitions: estimating (S204) a cell state of each of the cell partitions based on a target cell state parameter corresponding to the cell partition, wherein the target cell state parameter is determined based on the first cell state parameter of each cell in each of the cell partitions; under a condition that there are no multiple cell partitions in the battery, partitioning (S207) the cells based on the first cell state parameter of each cell to assign the cells among which a deviation of the first cell state parameter is within the first deviation range to a same cell partition, and performing (S208) the following step for each of the cell partitions: estimating the cell state of each of the cell partitions based on the target cell state parameter corresponding to the cell partition; and estimating (S104, S209) a battery state of the battery based on the cell state of each of the cell partitions in the battery. <EOS>