There are growing interests in organic thermoelectric (TE) materials，especial with conjugated polymers, seeking for environmental friendly and sustainable energy materials. The latest works revealed that conducting coordination polymers display great potential for the development of organic TE materials. A metal-1,1,2,2-ethenetetrathiolate (ett) coordination polymer poly[Kx(Ni-ett)] exhibits the highest ZT value of 0.2 at 440 K among n-type organic thermoelectric materials according to our previous report. However, the uncertainty of the polymer structure hinders the understanding of physical mechanism behind its performance and a rational enhancement. Another shortcoming of this polymer is that it is insoluble and infusible, which heavily affects their processability and making it is difficult to be integrated with a micro- or flexible device for cooling or power generating. To solve these problems, we have developed a electrochemical deposition method to grow thin films of poly(nickel ethenetetrathiolate) on different insulation substrates. The obtained films displayed improved molecular ordering and significantly enhanced TE performance. The ZT value can reach up to 0.3 at room temperature and a highest power factor of 950 μWm-1K-2 is obtained under 400 K.