SP Energy Networks says it has started work on the wooded pole line between the two towns.
It will also upgrade the substation at Wem, with the firm saying the work will "boost network capacity and resilience throughout North Shropshire".
The project was granted planning permission by Alok Sharma, Secretary of State for Business Energy and Industrial Strategy (BEIS), in March 2020.
SP Energy Networks said it will help it to cope with increased demand for power in the coming years "from low carbon technologies such as electric vehicles and electric heating".
Pre-engineering work took place in 2020, but the main construction has started this month, and is scheduled to be completed by the end of this year.
Mark Sobczak, Head of 132kV Programmes at SP Energy Networks, said: “This is our largest reinforcement project in England and Wales, which will help increase network resilience and enable future growth to support decarbonisation across North Shropshire.
“It underlines our commitment as a Distribution Network Operator (DNO) to lead the way towards achieving net zero emissions targets and future proof our network.
“As the country makes its green economic recovery, we are investing to make sure that people in North Shropshire can make a smooth transition to more environmentally-friendly energy solutions, supported by a resilient network.”